Air strikes by Syrian warplanes killed at least 28 people Thursday, including 11 civilians in a raid on Islamic State (IS) jihadists, a monitoring group said.
"Warplanes carried out six raids on Thursday against Al-Bab" in the north of the country, the Britain-based Syrian Observatory for Human Rights said.
"Eleven people were killed, including women and children, and 17 were wounded when fighters (jets) fired rockets into a crowded area near a market in the town," southeast of Aleppo city.
IS has been pulling fighters out of the area, with some of its commanders saying the move was in case of Syrian army bombardment and possible American air strikes.
US President Barack Obama said Wednesday he had ordered the American military to expand its operations against IS, which has seized a swathe of Iraq and Syria and committed horrifying atrocities.
"Our objective is clear: we will degrade, and ultimately destroy, ISIL through a comprehensive and sustained counter-terrorism strategy," Obama said, using an alternative acronym for the group.
"I will not hesitate to take action against ISIL in Syria, as well as Iraq."
Elsewhere Thursday, air strikes on rebel-held Douma near Damascus killed 17 people, including four children, Observatory chief Rami Abdel Rahman said.
Douma, north of the capital, has been under siege for more than a year.
Fighting at Marea north of Aleppo Thursday killed four rebels from a group holding the area and 11 IS fighters seeking to seize it, the Observatory said.
And in the central province of Hama, the Observatory said regime forces supported by Iranian officers retook a large part of the Halfaya area from rebels and jihadists of the Al-Qaeda-linked Al-Nusra Front.