A suicide bomber killed at least 45 people when he drove a car laden with explosives into a compound run by local militias in Aden on Monday, Medecins Sans Frontieres said, in one of the deadliest attacks in the southern Yemeni port city.
The official said at least 60 other people were brought into a nearby hospital run by the medical charity in Aden's Mansoura district.
The Islamic State has claimed responsibility for the attack through its news agency.
A security source said the attack targeted a school compound where conscripts of the Popular Committees, forces allied to the internationally recognised President Abd-Rabbu Mansour Hadi, were gathered for breakfast.
The blast rocked the area and sent debris flying, sending residents fleeing, one witness said.
Islamist militants have exploited an 18-month-old civil war between the Houthis and Hadi's supporters and launched a series of attacks targeting senior officials, religious figures, security forces and compounds of the Saudi-led Arab military coalition which supports Hadi.
