At least 15 people have been killed in Yemen’s coastal city of Aden, a local resident said, in an attack claimed by the local affiliate of the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group. The resident, who wished to remain anonymous, told Al Jazeera that several people died in the city’s Khormaksar district on Sunday after an explosives-rigged car blew up outside the criminal investigation department (CID) building. Armed men, some of whom were wearing military fatigues, then proceeded to storm the facility where clashes were “still ongoing,” the source said. Also in Aden on Sunday, a car bomb targeted the Dar Saad-based office of Yemen’s Islah (Congregation for Reform) party, the country’s largest opposition group, the source said. The building was abandoned and there were no reports casualties, the source said. ISIL took responsibility for the attack on the CID building, according to its Amaq,website, claiming the armed group killed around 50 officers. Earlier on Sunday, images posted on social media showed a pitched street battle between security personnel and unknown fighters near the CID building.