ISIS executed 700 people from Syrian tribe: Monitoring group

Beirut/Amman: The Islamic State militant group (ISIS) has executed around 700 members of a tribe it has been battling in eastern Syria during the past two weeks, the majority of them civilians, a human rights monitoring group and activists said on Saturday.

The Syrian Observatory for Human Rights, which has tracked violence on all sides of the three-year-old conflict, said that reliable sources reported beheadings used to execute several people of the al-Sheitaat tribe, which is from Deir al-Zor province.

The conflict between Islamic State and the al-Sheitaat tribe, whose members come to around 70,000, flared after the militants took over two oil fields in July. "Those who were executed are all al-Sheitaat," Observatory director Rami Abdelrahman said by telephone from Britain. "Some were arrested, judged and killed."

The militant group has been advancing across northern Iraq in recent weeks and massacring and driving out thousands of civilians from their homes prompting the first U.S. air strikes in Iraq since the withdrawal of American troops in 2011. The insurgents are also tightening their grip on Syria, of which they now control roughly a third, mostly rural areas in the north and east.

More than 170,000 people have been killed in Syria's civil war, which pits overwhelmingly Sunni Muslim rebels against President Bashar al-Assad, a member of the Shi'ite-derived Alawite minority, backed by Shi'ite militias from Iraq and Lebanon.

Islamic State was condemned on Friday in a U.N. Security Council resolution for "gross, systematic and widespread abuses of human rights and violations of international humanitarian law."