In this task, you are given news articles and you need to generate a highlight, i.e., a short summary, with a maximum length of 10 lines.

Mexico City (CNN) -- The runner-up in Mexico's presidential election said Friday he still won't accept a vote count, even after the country's electoral tribunal upheld the legality of the election and officially declared Enrique Pena Nieto as the winner. Leftist candidate Andres Manuel Lopez Obrador has not conceded the July 1 election, citing allegations of electoral fraud by the victorious Institutional Revolutionary Party, known as the PRI. The electoral tribunal on Thursday rejected a demand by Lopez Obrador's coalition, the Progressive Movement of Mexico, to invalidate the presidential election, which he lost by 6 percentage points. On Friday, it validated the final results, officially naming Pena Nieto as president-elect. "The elections were not clean or free or authentic. As such, I will not recognize the illegitimate power that came from vote-buying and other grave violations of the constitution and the laws," Lopez Obrador said. The candidate called on his followers to demonstrate in Mexico City's historical square, the Zocalo, on September 9. Lopez Obrador narrowly lost another presidential race in 2006. Back then, he refused to recognize the new government and called his supporters into the streets. He went on a national tour, where he drummed up support, calling himself the "legitimate president of Mexico." It was unclear if he would call for similar demonstrations now. In a unanimous decision announced Thursday, the electoral tribunal ruled that the demand to invalidate the election was "unfounded." The tribunal found that the leftist coalition that brought the charges didn't prove any constitutional violations and didn't show that the process wasn't free and fair. Critics of the process said the irregularities included illegal campaign spending, secretive financing and coercion of voters. Read more: Vote-buying allegations persist after Mexican election . When the allegations surfaced immediately after the vote, election officials recounted the votes in more than half of the ballot boxes individually. Among the bigger controversies were allegations that PRI campaigners passed out hundreds of supermarket gift cards in exchange for votes. The electoral tribunal said that the coalition could prove only that PRI officials gave the cards to supporters, and not to the general public in exchange for votes. Pena Nieto is expected to be sworn in on December 1. CNNMexico's Belen Zapata and Tania Montalvo contributed to this report.
NEW: Mexico's electoral tribunal declares Enrique Pena Nieto as president-elect .
NEW: He is expected to take office on December 1 .
Andres Manuel Lopez Obrador says he will not accept the ruling .
He calls for a demonstration in Mexico City's main square .

The discovery of a slain Palestinian teen in Jerusalem early Wednesday further inflamed tensions in a region already unsettled over the killings of three Israeli teens, not to mention decades of entrenched enmity between all sides. Mohammad Abu Khedair, 17, was heading from his home to a mosque in the middle-class neighborhood of Shuafat for prayers around 4 a.m. when three men forced him into a car and drove off, his father, Hussain Abu Khedair, told CNN. His body was found about an hour later at a forest in Jerusalem. The killing quickly triggered condemnations from Palestinian and Israeli leaders, as well as from the United States. Abducted Palestinian teen was kind, beloved . Those who spoke out passionately included an uncle of one of the three Israeli teens whose bodies were found earlier this week. He called the young Palestinian's killing "a forbidden action, and it has no forgiveness." "Any act of revenge of any kind whatsoever is completely inappropriate and wrong. Murder is murder," said Yishai Frankel, uncle of Naftali Frankel, a 16-year-old dual Israeli-American citizen, to Israel's Channel 2. "One should not differentiate between bloods, be it Arab or Jew. Israeli authorities are probing Wednesday's death, with police spokesman Micky Rosenfeld tweeting this effort will try to determine if it is a "criminal or nationalistic" act -- the latter term referring to a politically motivated act in retaliation for the Israeli  teens' killings. Mark Regev, a spokesman for Prime Minister Benjamin Netanyahu, told CNN late Wednesday that investigators "at this stage cannot say who did this killing." This came hours after Netanyahu's office promised a speedy investigation to find "who is behind this despicable murder and the background to this act," according to a statement from his office. "Netanyahu calls on all sides not to take the law into their own hands. Israel is a country of law and everyone is ordered to act according to the law." The killing riled many Palestinians, particularly in Jerusalem. But it didn't happen in isolation. Israelis and Palestinians continue to trade blows -- over longstanding issues unrelated to Abu Khedair's death -- through rocket attacks and airstrikes. All this violence, from various angles, leads to one big question: When will it stop? Report: Body was 'charred and bore signs of violence' "Settlers" kidnapped the teenager and his body "was charred and bore signs of violence," according to the Palestinian state news agency WAFA. DNA, through saliva samples, was used to positively identify the boy, his father said. Rosenfeld told the Jerusalem Post the teen had significant burn marks. The same Israeli publication also reported police are looking into previous kidnap attempts on members of the teenager's family related to a personal dispute. Yet Hussain Abu Khedair, the boy's father, blamed Israelis and vehemently denied reports that this may have been tied to any sort of family dispute. "Netanyahu is responsible for the crime," the father told CNN, "because he is the one who is giving the settlers the cover and supporting them." The teen's cousin, Majdi Abu Khedair, said whoever carried out the abduction was driving a car that had been used in an attempted abduction two days ago. A similar claim was made to Haaretz by Knesset member Ahmed Tibi. The cousin passionately suggested: "The Israeli police and Israeli government should do the same as they have done in Hebron: Demolish and blow the settler houses who have done this crime." The Israeli military destroyed the homes of the two suspects in the killings of the three Israeli teens. When confronted with this suggestion, Regev insisted "we are totally color blind when it comes to this sort of criminal act." "There's no difference between a Jewish resident of Jerusalem or an Arab resident of Jerusalem," the spokesman said. "... Police will get to the bottom of this." "It is sickening to think of an innocent 17-year-old boy snatched off the streets and his life stolen from him and his family," said Secretary of State of John Kerry, who talked with Netanyahu by phone about the situation. "There are no words to convey adequately our condolences to the Palestinian people." He noted that both Israeli and Palestinian officials have condemned it, and he added to Netanyahu's call. "Those who undertake acts of vengeance only destabilize an already explosive and emotional situation." Palestinian Authority President Mahmoud Abbas, who heads the Fatah party and is based in the West Bank, called Mohammad Abu Khedair's father and promised that those behind his abduction and death will be brought to justice, WAFA, the Palestinian state news agency, reported. And Hamas -- the militant Islamic organization that controls Gaza -- said in a statement that it holds the "Israeli occupation (fully) responsible," adding that the incident "exposes (Israel's) ugly ... racism" and "refutes the Israeli narration of being the victim all the time." Anger, clashes in Palestinian neighborhoods of Jerusalem . As news of the boy's death spread, public anger in Palestinian neighborhoods of Jerusalem rose to levels rarely, if ever, seen since the Second Intifada, or uprising, last decade. That led to several clashes around the city, the biggest of which was centered in Shuafat. Residents there threw stones at security forces and the Israeli authorities responded with occasional volleys of stun grenades or tear gas. Some protesters attacked two Palestinians whom they mistook for undercover Israeli police, The Jerusalem Post reported. The clashes expanded and continued through midnight in the Palestinian neighborhood, with a large amount of Israeli forces on hand. In Suwwaneh, Palestinians threw rocks at a nearby settlement and several of them were injured by rubber bullets, witnesses said. And some tossed Molotov cocktails at an Israel settlement in Silwan, outside Jerusalem's Old City. The Palestinian Red Crescent Society reported that more than 100 were injured, most of them in Shuafat, in the clashes. There were concerns that the Palestinian teenager's funeral could spark further unrest. But his father said Thursday he was still waiting to hear from Israeli authorities when the body would be handed over to the family. "The autopsy should be done around 1 p.m., and then I am supposed to wait for a call," Hussain Abu Khedair said on Palestinian television. "We will not bury my son at night," he said. "We will do it during the day. If they purposely delay, we will do it during the day even (if that means) tomorrow." Israeli airstrikes into Gaza . Meanwhile, the dangerous back-and-forth between Gaza and Israel was erupting yet again. Rockets from the Palestinian territory into Israel was met by at least eight airstrikes within about an hour early Thursday. Three hit a Hamas intelligence building in Gaza city, while at least one struck the Qassam training camp in Beit Hanoun. Palestinian medical sources reported at least 10 injured, one of them seriously. Israel Defense Forces said the airstrikes -- going after 15 Hamas targets -- were in response to the firing of more than 20 rockets into Israel since Wednesday. This is in addition to other actions -- including the arrests of hundreds of Hamas activists, the demolition of homes and the closure of dozens of institutions in Gaza, according to Netanyahu -- targeting Hamas and focused in Gaza. This action follows the abduction of Israeli teens Eyal Yifrach, Gilad Shaar and Naftali Frankel as they were on their way home from school June 13; the three were found dead on Monday in a West Bank field. Hamas praised the kidnappings but denied that it was responsible for what happened. It warned that if Netanyahu "brings a war on Gaza, the gates of hell will open to him." At the teens' funerals, Netanyahu said the country would avenge their deaths at "the hands of evil men." "A broad moral gulf separates us from our enemies," he said. "They sanctify death; we sanctify life. They sanctify cruelty and we mercy and compassion. That is the secret of our strength." Opinion: Teens' killing hurts Israelis, bad for Palestinians . Opinion: Slain teens call for justice, not escalation .
The boy's father says he's waiting to hear when authorities will hand over the body .
Israeli military says its airstrikes were focused on 15 Hamas targets in Gaza .
This comes amid Palestinian anger over the kidnapping, killing of a teen .
Israel vows to get those responsible; late teen's father blames Netanyahu .

(CNN) -- At least 13 people were killed and 20 others were injured when a severe storm tore through the Buenos Aires area, state media reported Thursday. Residents of the city awakened to crumbling walls, crushed cars, fallen trees and scattered branches after heavy rain, wind and hail hit Wednesday night, the state-run Telam agency said. "The level of virulence of this storm is not normal," said Diego Santilli, the city's environment minister, according to Telam. "The winds were similar to those of a tornado." One resident told the news agency that the Parque Avellaneda neighborhood "looks like they threw a bomb." Fallen trees blocked streets. A wall in at least one historic building collapsed, Telam said. Damage occurred within the city limits and also in the surrounding province, where at least nine people were killed when they were crushed or electrocuted, Telam said. Wind gusts ranged from 100 kph to 120 kph (62 mph to 75 mph), said Luciano Timerman, a provincial emergency official, Telam reported. Authorities evacuated 500 people in the western and southern areas of the metropolitan area as the storm raged, Timerman said. They were returning to their homes on Thursday.

NEW: Death toll rises in Buenos Aires-area storm, officials say .
Residents awaken to crumbling walls, crushed cars and fallen trees .
"The level of virulence of this storm is not normal," Buenos Aires official says .
A provincial official says wind gusts reached up to 120 kph (75 mph)