23 December 2014
Last updated at 15:43
Islamic State militants control large swathes of both Syria and Iraq
Three months of US-led air strikes have killed at least 1,171 people, mostly Islamic State (IS) militants, in Syria, a UK-based monitoring group has said.
The Syrian Observatory for Human Rights (SOHR) said most of the dead were foreign fighters who had joined the IS cause.
The group also said that 52 civilians – including women and children – had been killed in the strikes.
Large swathes of territory in Syria and Iraq fell to IS earlier this year.
A US-led coalition has been carrying out air strikes against IS in Syria since the end of September.
Earlier this week the US commander in charge of the mission, Lt Gen James Terry, said it would “at least take a minimum of three years” to defeat IS.