Two car bombs exploded Wednesday in Libya's eastern city of Derna, an Islamist hotspot, residents and a military source said. There was no immediate word on casualties. The area around Derna, located east of Benghazi, has seen heavy fighting in recent weeks between Islamic State militants and a rival Islamist group. ISIS fighters left the city last month but had taken up new positions outside Derna, residents said. ISIS has thrived in the North African oil producer since two rival governments began fighting for control, leaving a security vacuum, four years after the civil war that ended the rule of Moammar Gadhafi.