US-led forces targeted Islamic State militants in Syria with six air strikes and conducted another 17 strikes against the group in Iraq from Tuesday to Wednesday morning, the US military said.

In Syria, there were two strikes involving attack and fighter aircraft near Al Hasakah and four near Kobani, it said in a statement released on Wednesday. In Iraq, the strikes were conducted with fighter and attack planes as well as drones near Bayji, Fallujah, Mosul, Ramadi, Sinjar and Tal Afar, the US military statement said.

"All aircraft returned to base safely," it said.