Question: Who claimed responsibility for the hotel attack that killed Carsten Thomassen?

Context paragraphs:
Journal of Graph Theory: The Journal of Graph Theory is a peer-reviewed mathematics journal specializing in graph theory and related areas, such as structural results about graphs, graph algorithms with theoretical emphasis, and discrete optimization on graphs.  The scope of the journal also includes related areas in combinatorics and the interaction of graph theory with other mathematical sciences.  It is published by John Wiley & Sons.  The journal was established in 1977 by Frank Harary.  The editors-in-chief are Paul Seymour (Princeton University) and Carsten Thomassen (Technical University of Denmark).

Carsten Thomassen: Carsten Thomassen (born August 22, 1948 in Grindsted) is a Danish mathematician.  He has been a Professor of Mathematics at the Technical University of Denmark since 1981, and since 1990 a member of the Royal Danish Academy of Sciences and Letters.  His research concerns discrete mathematics and more specifically graph theory.

December 2010 Bajaur bombing: On 25 December 2010, at least 47 people were killed and over 100 others injured, after a female suicide bomber detonated her explosives in a large crowd of people displaced by fighting, who were collecting food at a distribution centre of the World Food Programme in the Pakistani town of Khar, which is located within the Bajaur tribal region, of north-western Pakistan.  It was later reported by witnesses, that the bomber dressed in a full-length burka had reportedly thrown a grenade after resisting search, to which then the bomber proceeded to detonate her explosives.  Several police officials confirmed the bomber was a woman, as opposed to the more likely occurrence of a man wearing the burka as a disguise, in order to successfully conduct this suicide attack.  It was also known that those in this crowd were predominantly displaced members of the Salarzai Tribe, which has supported Pakistan Army operations against the Pakistani Taliban within the Bajaur tribal regions.  Those dozens of people injured in this suicide attack were apparently later taken to local hospitals via means of helicopters.  Local Witnesses, including that of a government official at the main government hospital within the region, Dosti Rehman, claimed that he had personally counted some 40 bodies.  However there are concerns that the death toll could very likely rise, as the official stated that several of those injured, as a result of this suicide attack were apparently in a critical condition at the local hospitals.  This particular bombing acts as one of a string of recent suicide attacks, which have occurred with near impunity, predominantly throughout Pakistan's north-western, Khyber Pakhtunkhwa Province, of north-western Pakistan.  No particular militant group has of yet claimed responsibility for this suicide attack, although the Pakistani Taliban are strong suspects.  The Bajaur tribal region has reportedly seen several Pakistan Army military operations in recent years, however such suicide attacks still continue throughout the region with near impunity.  The Pakistani Prime Minister, Yousaf Raza Gillani later condemned this suicide attack, and claimed that such military offensives would continue against the Pakistani Taliban.  This statement will be met with a certain degree of approval in the U.S, as Pakistan has recently been pressured to launch a major ground-offensive in the nearby North Waziristan tribal region, in order to root-out and destroy the last major remaining safe-haven for Radical Islamist and Pakistani Taliban insurgents within the country.  The U.N World Food Programme later suspended its food distribution activities in the Bajaur tribal region, as a security precaution to this suicide attack.  This suicide bombing was strongly condemned by U.S president, Barack Obama.  The Pakistani Taliban later claimed responsibility for this suicide attack.  This suicide bombing was officially declared the first such suicide attack to involve a female in Pakistan.

Carsten Thomassen (journalist): Carsten Thomassen (15 May 1969 – 14 January 2008) was a Norwegian journalist, political commentator and war correspondent for the Norwegian daily newspaper "Dagbladet".  He had earlier covered the 2004 Indian Ocean earthquake from Thailand and Indonesia.  He was killed in the 2008 Kabul Serena Hotel attack in Kabul, Afghanistan.

23 May 2016 Yemen bombings: On 23 May 2016, two suicide bombings, conducted by the Islamic State of Iraq and the Levant, killed at least 45 potential army recruits in Aden, Yemen.  The first attack, which targeted a lineup, killed 20.  The second attack, which occurred inside the base, killed 25.  The Islamic State of Iraq and the Levant claimed responsibility for the attack.  The attack was preceded by the 2016 Yemen Police bombings in the Yemeni city of Mukalla, which killed more than 48 people and injured over 60.

2014 Kabul Serena Hotel attack: The 2014 Kabul Serena Hotel attack was a mass shooting at the restaurant of the Kabul Serena Hotel, in Kabul, Afghanistan on March 20, 2014 for which the Taliban claimed responsibility.  Four teenage gunmen entered the restaurant of the hotel, opening fire with handguns against patrons and sparking a three-hour standoff with Afghan security forces.  At least nine people were reported killed in the assault, including five Afghans and four foreigners.  Among the victims was former Paraguyan diplomat Luis Maria Duarte, who was in the country as an international observer in the upcoming Presidential elections.  Afghan authorities later announced that four women and two children were among the victims, which included nationals of New Zealand, Pakistan, India and Canada.  At least two of the hotel's security guards were injured during the assault as well.

2015 Arish attack: The 2015 Arish attack was a terrorist attack on a hotel in the coastal city of Al-Arish, Egypt, on 24 November 2015.  A group of militants approached the heavily guarded hotel with a car bomb, but Egyptian security forces opened fire at the vehicle, blowing it up before it could reach the building.  One of the two attackers managed to get inside the hotel, where a number of people were injured and killed as a result of gunfire and a subsequent suicide bombing.  Authorities reported at least seven dead, including two judges who had been in Al-Arish to supervise the country's second round of parliamentary elections, held the day before.  The Islamic State's Wilayat Sinai offshoot claimed responsibility in a statement released later the same day.

Itamar attack (2002): The Itamar attack, was an attack that took place on Thursday night of 20 June 2002 around 21:00 in which two Palestinian militants broke into a civilian house in the Israeli settlement of Itamar in the West Bank, killing the Shabo family, murdering a mother and her three sons, while injuring two children.  Later on the militants also killed the commander of the rescue squad during his attempt to free civilians trapped in the house.  The two gunmen were killed and eight Israelis were wounded when soldiers stormed the house.  This was the second attack on Itamar in less than a month.  The Popular Front for the Liberation of Palestine claimed responsibility for the attack.

Togo national football team attack: The Togo national football team bus attack was a terrorist attack that occurred on 8 January 2010 as the Togo national football team traveled through the Angolan province of Cabinda on the way to the 2010 Africa Cup of Nations tournament, which began on 10 January.  A little-known offshoot of the Front for the Liberation of the Enclave of Cabinda (FLEC), a group promoting independence for the province of Cabinda, known as the Front for the Liberation of the Enclave of Cabinda - Military Position (FLEC-PM), claimed responsibility for the attack.  Bus driver Mário Adjoua, the team's assistant manager Abalo Amelete, and media officer Stanislas Ocloo were killed, with several others injured.  Secretary General of the FLEC-PM Rodrigues Mingas, currently exiled in France, claimed the attack was not aimed at the Togolese players but at the Angolan forces at the head of the convoy.  Authorities reported two suspects were detained in connection with the attacks.

2008 Kabul Serena Hotel attack: The 2008 Kabul Serena Hotel attack was an attack on the gym of the Kabul Serena Hotel, in Kabul, Afghanistan on January 14, 2008 for which the Taliban claimed responsibility.

Supporting paragraphs: Carsten Thomassen (journalist) 2008 Kabul Serena Hotel attack
Answer: the Taliban