A strong earthquake has hit the impoverished country of Haiti, where a hospital has collapsed and people are screaming for help.

The U.S. Geological Survey says the quake had a preliminary magnitude of 7.3. It occurred Tuesday afternoon and was centered about 14 miles (22 kilometers) west of the Caribbean nation's capital, Port-au-Prince.

An Associated Press videographer saw the collapsed hospital in Petionville.

No further details are immediately available.