Syrian activists say Islamic State fighters have launched an attack on a key air base in eastern Syria.
The base in Deir al-Zour province is one of the last remaining outposts the government controls in a region where the Islamic State group has largely taken over.
The Britain-based Syrian Observatory for Human Rights said Thursday the militants began the attack with a car bombing, and that 19 Syrian soldiers and seven militants have been killed in the fighting.
Meanwhile, Syrian President Bashar al-Assad says U.S.-led airstrikes against the Islamic State group have not been effective.
In an interview published by the French magazine Paris Match, Assad said the strikes have not made a difference in the effort to battle the militants. He also called the military flights over Syrian territory an "illegal intervention" that violate Syria's sovereignty.
U.S. Secretary of State John Kerry told a meeting of 60 coalition partners Wednesday that the airstrikes against the militants in Syria and Iraq have made it harder for the Islamic State group to launch attacks.
Also Wednesday, a top U.S. general said the militant group has set up training camps in eastern Libya.
General David Rodriguez said Wednesday the Pentagon is ruling out any military strike on those camps at this time, calling the activities there small and very nascent. He said the Pentagon suspects those inside the camps are local militias trying to make connections and that officials will monitor the situation.
