US-led strikes 'killed 2,079 people in Syria'

US-led coalition airstrikes in Syria have killed 2,079 people, including 66 civilians, since the start of the campaign against Islamic State (IS) militants last September, a monitoring group said on Thursday.

"At least 1,922 fighters from IS, mostly foreigners, have been killed since 23 September 2014 in raids and aerial attacks by the international coalition on IS positions and oil refineries" throughout Syria, the Syrian Observatory for Human Rights said.

However, the Britain-based monitoring group added that ten children and six women were also among the killed. 

The United States stated that reports of civilian casualties are taken "seriously" and that it has a process to investigate each allegation.

Reuters news agency added that Washington justified its action in Syria under Article 51 of the UN Charter, which covers an individual or collective right to self-defence against armed attack.

The strikes targeted IS positions in the central province of Homs, as well as Aleppo in the north, Hasakeh in the northeast, and Deir Ezzor to the east.

They also struck the northern province of Raqa, where the provincial capital of the same name has become the centre of IS's self-styled "caliphate".

The toll also included 90 fighters from IS' rival and al-Qaeda Syrian affiliate al-Nusra Front, most of whom were killed in coalition strikes on their strongholds in northern Syria. It also included one Islamist rebel who was being held by IS.

More than 220,000 people have been killed and at least 11.2 million displaced since the beginning of the war.