BEIRUT - A Syrian government air strike killed commanders of the Islamic State group in the eastern province of Deir al-Zor on Thursday, including Syrians, Arabs and foreigners, the Syrian Observatory for Human Rights, which monitors the war, said.Syrian state TV reported that the army "eliminated more than 10 terrorists" in an attack east of Deir al-Zor airport, including two men it named as Islamic State leaders in the province, and destroyed 14 armored vehicles.The Observatory, which says it gathers information from all sides in the Syrian conflict, reported that Syrian war planes had struck a building used as a headquarters by Islamic State while a meeting of its commanders was underway.