A powerful earthquake has struck Haiti, killing at least 304 people and injuring more than 1,800.

The 7.2-magnitude quake hit the west of the country, toppling and damaging scores of buildings.

The prime minister said there was "extensive damage" and declared a month-long state of emergency.

The tremor was felt in the densely-populated capital of Port-au-Prince, some 125km away, and in neighbouring countries.

Haiti is still recovering from a devastating 2010 earthquake.