The U.N. report issued Saturday said violence killed 856 civilians and 417 members of Iraq's security forces. It said attacks wounded 2,010 Iraqis.

The worst-hit city was Baghdad, with 379 civilians killed.

The U.N. says the figures do not take into account causalities in Anbar province nor some other militant-held parts of Iraq.

The October count apparently did not include the victims of the recent mass killings conducted by ISIS group militants in Anbar province against Sunni tribesmen.

The U.N. has said September's death toll was 1,119 Iraqis killed.

ISIS group terrorists lined up and shot dead at least 50 tribesmen and women in Iraq's Anbar province, officials said Saturday, the latest mass killing committed by the group.

The shooting happened late Friday in the village of Ras al-Maa, north of the provincial capital of Ramadi, Anbar councilman Faleh al-Issawi said.

Later ISIS militants executed at least 220 Iraqis in retaliation against a tribe's opposition to their takeover of territory west of Baghdad, security sources and witnesses said.

Two mass graves were discovered on Thursday containing some of the 300 members of the Sunni Muslim Albu Nimr tribe that ISIS had seized this week. The captives, men aged between 18 and 55, had been shot at close range, witnesses said.