Hurricane Katrina has battered the southern part of the U.S. state of Florida with high winds and heavy rain, leaving four people dead as it crossed the state to move out over the Gulf of Mexico.

Forecasters say Katrina is now likely to get stronger and perhaps make a second landfall in the Florida Panhandle early next week as a major hurricane.

The 11th named storm of this year's Atlantic hurricane season came ashore Thursday between Hallandale Beach and North Miami Beach, packing 130 kilometer-per-hour winds. It knocked down trees, flooded streets and left more than one million people without power.

The U.S. Coast Guard is searching for a family of five who went out boating Thursday morning and never reached their destination Cape Coral on Florida's southwest coast.