Syrian activists say IS has killed 12 captives in Palmyra

BEIRUT (AP) - The Islamic State group has killed 12 people it held captive in Syria's ancient Palmyra by shooting and beheading them, with some of the slayings carried out in the city's second-century Roman amphitheater, activists said on Thursday.

The extremist group had recaptured the city in December from government troops - nine months after IS was expelled from there in a Russia-backed offensive and while Syrian government forces were focused on retaking the eastern half of the city of Aleppo from rebels.

When they previously controlled Palmyra, IS militants had used the Roman amphitheater for public killings, including those in a video showing 25 boys with pistols shooting captured Syrian soldiers, the ancient colonnades visible in the background.

The Islamic State group has also destroyed ancient temples and other relics in the past, triggering fears among experts for remaining antiquities in the city. The city has been largely emptied out of its residents, following the government offensive in March last year.

The Britain-based Syrian Observatory for Human Rights and another activist network, the Palmyra Monitor, said the 12 captives were killed on Wednesday. They were captured as they tried to escape the IS offensive on Palmyra last month.

The Observatory said four teachers and government employees were beheaded in the courtyard of the Palmyra museum. The Observatory and the Palmyra Monitor said the others - four opposition fighters and four pro-government troops - were first shot, then beheaded in the Roman amphitheater or in a former Russian base in Palmyra.

The Observatory also said Thursday that IS militants during an ongoing assault in eastern Syria's Deir el-Zour province, hung the heads of six pro-government fighters in public, in different parts of the town of al-Mayadeen. There were no bodies attached to the heads, and it was not clear if the six were killed in battle or after they were taken captive.

Over the past year, IS has suffered defeats in both Syria and Iraq, losing several towns and cities it had captured in 2014. Its surprise re-taking of Palmyra came weeks before it went on a wide assault in Deir el-Zour, against the government controlled part of the city. Activists said it was the IS group's most aggressive onslaught on the government area and a nearby military air base in a year.

The Islamic State group is feared for its reign of terror and gruesome killings, including beheadings, often carried out in public.