At least 724 people were killed and some 2,800 injured from Haiti’s devastating earthquake, the country’s civil-protection agency said Sunday.

At least 500 of the fatalities were in the country’s southern peninsula where Saturday’s magnitude 7.2 quake hit, Jerry Chandler, head of Haiti’s civil-protection agency, told reporters.

The fatality count was expected to rise further as Haitians frantically searched for hundreds of people still missing on Sunday.

In the hard-hit southern city of Les Cayes, more than 1,500 buildings were destroyed, including churches, hospitals and schools, Mr. Chandler said.

Many residents in southern Haiti spent the night sleeping outdoors, afraid their homes would collapse as aftershocks continued to rattle the nation.