Cairo (AFP) - Here is a list of known killings by militants or movements linked to the jihadist Islamic State group, which announced Sunday it had beheaded 21 Egyptian Coptic Christians in Libya.
The IS, accused of crimes against humanity by the United Nations, has stepped up atrocities, including beheadings, abductions and crucifixions, in the regions of Iraq and Syria it controls.
- August 19: IS posts a video of the decapitation of US freelance photojournalist James Foley, 40, who was seized in northern Syria in November 2012. It threatens to execute a second US journalist, Steven Sotloff, 31, in response to US strikes on jihadist positions in Iraq, which began in August.
- September 2: IS says in another propaganda video that it has beheaded Sotloff, a freelance reporter kidnapped on August 4, 2013, in Aleppo.
- September 13: IS claims to have beheaded British aid worker David Haines, 44, who was seized in March 2013 while working for a Paris-based non-governmental organisation.
- September 24: The IS-linked Jund al-Khilifa, or "Soldiers of the Caliphate," says in a video it has decapitated French tourist Herve Gourdel, 55, who was abducted in Algeria.
- October 3: An IS video says it has beheaded British aid volunteer Alan Henning, 47, in Syria, in revenge for British strikes on jihadist positions in Iraq.
- November 16: The IS claims to have killed Peter Kassig, 26, an American aid worker kidnapped in Syria, as a warning to Washington.
The same video shows the gruesome simultaneous beheadings of around 15 men described as Syrian military personnel.
- January 8: The Libyan branch of IS says it has killed Tunisian journalists Sofiene Chourabi and Nadhir Ktari, missing in eastern Libya since September.
- January 24 and 31: IS videos claim the beheading of Japan's Haruna Yukawa, 42, and his friend and fellow captive, journalist Kenji Goto, 47.
- February 3: Jordanian pilot Maaz al-Kassasbeh, 26, is shown in an IS video being burned alive in a cage after being captured in December when his F-16 crashed in Syria during a mission with the US-led coalition.
- February 15: the IS posts a video showing the beheading of 21 Egyptian Coptic Christians in Libya, saying they had been killed for their faith.
In addition, on February 6, IS announced the death of American aid worker Kayla Mueller, 26, saying she had been killed in a coalition air strike in northern Syria. On February 10 her death was confirmed by her family and the White House, which denied that she was killed in a raid.
SYRIA: The Britain-based Syrian Observatory for Human Rights says that from June to November, 2014, IS killed nearly 1,500 people, mostly civilians.
LEBANON: the army has fought jihadists from neighbouring Syria in the east. Twenty-five soldiers and police were abducted in August 2014 by IS and Al-Nusra Front, the Syrian branch of Al-Qaeda. Four have been murdered.
IRAQ: the UN High Commissioner for Human Rights in January denounced the "monstrous" contempt for human life there of IS, which has killed dozens of civilians this year.