Rescuers are picking through rubble in a desperate search for any survivors.
Homes, churches and schools were among buildings flattened in the quake. Some hospitals were left overwhelmed and in need of supplies.
An unknown number of people are missing and about 5,700 have been injured, officials say.
The disaster compounds problems facing the impoverished nation, which is already reeling from a political crisis following the assassination of its president last month.