BEIRUT (Reuters) - Air strikes by United States-led forces in Syria have killed 865 people, including 50 civilians, since the start of the campaign in late September against the Islamic State in Iraq and Syria (ISIS) militants, a group monitoring the war said on Wednesday.

The Britain-based Syrian Observatory for Human Rights said the majority of the deaths, 746, were ISIS fighters and said the actual figure could be much higher.

Eight of the civilians were children and five were women, the observatory said. It said 68 members of the Al-Qaeda-affiliated Nusra Front were also killed in the air strikes, which started early on Sept 23.