Activists say the Islamic State group did not hold Friday prayers in several mosques in its de facto capital of Raqqa in northern Syria, fearing Russian airstrikes.
The Britain-based Syrian Observatory for Human Rights said a drone carried out strikes on an IS-run camp near Raqqa on Friday. It had no word on casualties.
A Raqqa-based collective called Raqqa is Being Silently Slaughtered said several mosques were evacuated for fears of airstrikes.
The Observatory said air raids near Raqqa Thursday killed 12 extremists including a Tunisian and an Iraq. The Observatory said it was not clear if the nine air raids were carried out by Russian warplanes or those of the U.S.-led coalition.