Hurricane Gustav has crashed into western Cuba with sustained winds of 240 kilometers per hour.
The storm swept past Cuba's Isle of Youth and over its mainland late Saturday. At midnight UTC, Gustav's eye was about 105 kilometers west-southwest of Havana. Forecasters say Gustav could drop more than a half-meter of rain in some parts of the country.
The U.S. National Hurricane Center says Gustav is now an extremely dangerous category four hurricane on the five-point scale that measures a storm's intensity. Forecasters say the storm will likely continue to strengthen as it moves into the Gulf of Mexico toward the southeastern U.S. coast.
Gustav has claimed at least 80 lives in Jamaica, Haiti and the Dominican Republic.
Hurricane watches have been posted along a large portion of the U.S. coast between the states of Florida and Texas.
Some U.S. Gulf coast states Louisiana, Mississippi and Texas have started evacuating residents. The mayor of New Orleans, Louisiana, says he will order mandatory evacuation of the city on Sunday morning if the storm continues on its current course. New Orleans was devastated three years by Hurricane Katrina.
Separately, Tropical Storm Hanna is expected to move near the Turks and Caicos Islands in the Caribbean later Sunday or early Monday. Hanna has wind speeds of 85 kilometers per hour and is also expected to strengthen.
Some information for this report was provided by AP, AFP and Reuters.