BAGHDAD Iraqi forensic teams began on Monday excavating 12 suspected mass grave sites thought to hold the corpses of as many as 1,700 soldiers massacred last summer by Islamic State militants as they swept across northern Iraq. 
 
 The mass killings last June of Shi'ite soldiers from Camp Speicher, a former U.S. base outside the Sunni city of Tikrit, has become a symbol of the brutality of Islamic State fighters and their hatred for Iraq's Shi'ite majority. 
 
 The deaths showed Iraqis that the Islamic State fighters, who have also attacked ethnic and religious minorites as well as fellow Sunni Muslims opposing them, were a threatening new kind of foe. 
 
 The images of Shi'ite soldiers being machine-gunned in their hundreds, posted online by the jihadists, could rank as the deadliest single act of bloodshed during a decade of periodic sectarian war in Iraq. 
 
 The exhumation of burial sites on the late dictator Saddam Hussein's presidential compound came days after Islamic State militants were driven from the city by Iraqi forces and Shi'ite paramilitaries. 
 
 "We dug up the first mass grave site today. Until now we found at least 20 bodies. Initial indications show indisputably that they were from the Speicher victims," said Khalid al-Atbi, an Iraqi health official working with the forensic team sent to Tikrit. 
 
 "It was a heartbreaking scene. We couldn’t prevent ourselves from breaking down in tears. What savage barbarian could kill 1,700 persons in cold blood?" he asked. 
 
 Survivors of Speicher have described to Reuters their ordeal last June as the Iraqi military chain of command unraveled and Islamic State's Sunni fighters descended on Tikrit, rounding up Shi'ite soldiers for slaughter. 
 
 The victims' families, who often grow angry at Iraq's political class for failing to provide them proper answers, have wondered for months about the fate of their friends and loved ones. 
 
 "The only positive thing is the victory in Tikrit," said, Ali Hamad, whose cousin Kamal went missing at Speicher. 
 
 "We are happy. At least the families will soon know the fate of their sons and cousins," he said. 
 
 (Reporting by Ned Parker; Editing by Tom Heneghan) ||||| Story highlights A total of 47 bodies have been exhumed from two mass graves 
 
 Iraqis find mass graves inside presidential palace compound in Tikrit 
 
 ISIS claimed to have executed 1,700 Iraqi soldiers captured outside Camp Speicher 
 
 Tikrit, Iraq (CNN) Mass graves believed to hold Iraqi soldiers have been discovered in newly liberated Tikrit. 
 
 Up to 1,700 bodies may be recovered. ISIS claimed to have executed that many soldiers captured in June outside Camp Speicher, a fortified Iraqi base near Tikrit. 
 
 A total of 47 bodies have been exhumed from two of the 11 mass graves discovered in Tikrit, an Iraqi government official said Tuesday. Hundreds are believed to have been executed by ISIS in June 2014 
 
 Grieving Iraqis, apparently not related to the soldiers, gathered to pray over the bodies. When the first three bodies were found, 10 Iraqi soldiers saluted the dead by firing seven shots into the air. The national anthem was played while soldiers wept. 
 
 All the bodies were decomposed. Some had their hands bound, Damon said. The remains will be sent back to Baghdad for DNA tests to establish identify, said Ali Tahir, a director in the Iraqi morgue who was supervising the digging and extraction.
– In June, ISIS did the barbaric: slaughtered scores of soldiers at a base on the outskirts of Tikrit. With the city newly liberated, Iraqi forensic teams have now begun the grim process of excavating suspected mass graves thought to contain some of the 1,700 soldiers ISIS claims to have killed at Camp Speicher. The AP cites an official with the country's Human Rights Ministry who says eight sites within the complex of presidential palaces are being worked on; Reuters puts the number of suspected mass graves at 12. Another official yesterday told Reuters that "initial indications show indisputably" that a handful of bodies recovered yesterday are those of Speicher victims, though DNA testing will be carried out to confirm this. The AP notes that one clip aired on Iraqi state TV showed unearthed skeletal remains still wearing combat boots. A CNN reporter on the scene describes decomposed bodies with their hands still tied together. In making its claim, ISIS released photos showing soldiers being led to trenches and then facedown in them before and after their execution. Other videos showed masked gunmen bringing the soldiers to a bloodstained concrete river waterfront, shooting them in the head, and tossing them into the Tigris. Previous reports have stated that if the number of dead is indeed 1,700, the massacre would rank as by far the largest atrocity in the country in more than a decade.