BEIRUT (AP) — A powerful explosion ripped through a Syrian border post Thursday near a refugee camp on the border with Turkey, setting cars ablaze and killing at least five people, Syrian opposition activists and Turkish state media said.

The blast believed to have been caused by a car bomb tore through the Bab al-Salama border crossing, also wounding a large number of people taken to hospitals in the Turkish town of Kilis across the border. Thousands of people have fled from Aleppo through the border crossing in recent weeks because of the government’s escalated aerial bombardment there.