A storm has caused heavy rains in Haiti, triggering mudslides and flooding that killed at least 11 people.

For hours, heavy rains have pounded the capital, Port-au-Prince, turning streets into rivers and forcing motorists to abandon their cars. Flooding has also swept through crowded slums and tent camps housing thousands of people still homeless from Haiti's devastating earthquake last year.

Haiti's new president, Michel Martelly, has urged residents to keep calm as the storm passes over the city. Forecasters also say heavy rains could cause flash flooding in the neighboring Dominican Republic, along with other countries such as Cuba and Jamaica. In the Dominican Republic, at least 4,000 people have been evacuated and authorities issued alerts of possible severe flooding in several regions.

The severe weather arrived at the start of this year's Atlantic hurricane season, which runs from June 1 to November 30, and as Haiti copes with a cholera outbreak that has left thousands dead. Haiti is the Western Hemisphere's poorest country.