At least 33 people were killed in a US-led coalition strike on a school used as a centre for displaced people near a jihadist-held Syrian town, a monitor said Wednesday. 

The Syrian Observatory for Human Rights said the strike south of Al-Mansoura, a town held by the Islamic State group in the northern province of Raqa, "took place in the early hours of Tuesday." 

"We can now confirm that 33 people were killed, and they were displaced civilians from Raqa, Aleppo and Homs," said Observatory head Rami Abdel Rahman.