According to a civil defense official, Russian warplanes carried out over a dozen airstrikes on opposition-held neighborhoods, including a mosque, marketplace and hotel.

“Most of offices in town have been damaged and firefighters are struggling to put out the raging fire,” he said.

Syria has been locked in a vicious civil war since early 2011, when the regime of Bashar al-Assad cracked down on pro-democracy protests. According to the Syrian Center for Policy Research, at least 470,000 Syrians have died in the war.