Activists say the US-led coalition has launched several air strikes on positions of Islamic State group militants in northern and eastern Syria, most In the town of Kobani, near Turkey.
The UK-based Syrian Observatory for Human Rights and the Local Coordination Committees say some of the air strikes targeted the eastern town of Mayadeen.
The Observatory said the bombardment hit oil refineries near Mayadeen, sparking a huge fire.
Idriss Nassan, a local Kurdish official from Kobani, added that intense air strikes had hit members of the Islamic State group around the town.
Mr Nassan said Kurdish militiamen captured the Tel Shair hill that overlooks the town and brought down the black flag of the Islamic State group.
Kobani has been under attack for about a month.