Syrian helicopter gunship hits town held by Islamic State group, kills at least a dozen people

FILE - In this Sunday, Aug. 10, 2014 file photo, Syrian Kurdish Peshmerga fighters stand guard at a refugee camp in Derike, Syria. Islamic State militiamen backed by tanks defiantly marched on in Syria, capturing 21 Kurdish villages even as the international community strains to assemble a coalition that might destroy them. (AP Photo/Khalid Mohammed, File) (The Associated Press)

FILE - In this Sunday, March. 3, 2013 file photo, Kurdish female members, foreground and background, of the Popular Protection Units stand guard at a check point near the northeastern city of Qamishli, Syria. Islamic State militiamen backed by tanks defiantly marched on in Syria, capturing 21 Kurdish villages even as the international community strains to assemble a coalition that might destroy them. (AP Photo/Manu Brabo, File) (The Associated Press)

FILE - In this Sunday, Aug. 10, 2014 file photo, Syrian Kurdish Peshmerga fighters stand guard while displaced Iraqis from the Yazidi community make their way to cross the Syria-Iraq border in Derike, Syria. Islamic State militiamen backed by tanks defiantly marched on in Syria, capturing 21 Kurdish villages even as the international community strains to assemble a coalition that might destroy them. (AP Photo/ Khalid Mohammed, File) (The Associated Press)

Activists say Syrian government helicopter gunships have attacked a northern town held by Muslim militants, killing at least a dozen people and wounding dozens more.

The Local Coordination Committees say a barrel bomb dropped by a helicopter targeted a bakery Thursday morning in the town of Al-Bab, killing 12 and wounding dozens.

The Britain-based Syrian Observatory for Human Rights said the air raid killed at least 15, adding that the number is expected to rise as some of the wounded are in critical conditions.

Al-Bab is controlled by the Islamic State group that now controls swaths of territory stretching from northern Syria across much of northern and western Iraq.

More than 190,000 people have been killed since the 2011 start of Syria's conflict, now a multilayered civil war.