At least 48 people were killed Saturday when a car bomb struck a Syrian border town that has sheltered thousands of refugees fleeing Aleppo. The Syrian Civil Defense said the explosion tore through a bustling market area in the town of Azaz, which is about five kilometers from the Turkish border. The Syrian Observatory for Human Rights said the blast hit near a local court house run by rebel groups. Activists have warned that the death toll is likely to rise, as rescue workers have not made it through all the wreckage yet. The rebel-controlled town had served as a sanctuary for many people who fled the government's offensive in Aleppo late last year, with many opposition activists and civilians resettling in the area. The town is home to numerous camps for internally displaced people. No group has claimed responsibility for the bombing yet.