Hurricane Ike has strengthened to become a Category 3 storm with winds of 115 mph.

Some fluctuation in intensity is expected in the next day or two, the National Hurricane Center said. It is too early to say whether Ike might threaten land.

At 8 p.m. Eastern time, the eye of Ike was about 645 miles east-northeast of the Leeward Islands.

Ike is moving toward the west-northwest near 18 mph.

Ike is behind Tropical Storm Hanna, which is battering Haiti, where it has killed 26 people. Forecasters said it could turn back into a hurricane before hitting the southern coast of the U.S. this weekend.

In Haiti, thousands have fled to shelters to escape flooding caused by Hanna. Families scrambled onto rooftops to stay above floodwaters triggered by torrents of rain. U.N. soldiers are still unable to reach one badly flooded city.

A U.N. official said, "the situation is as bad as it can be" in Haiti. It's been pummeled by three storms in two weeks, and more than 100 people have died.

At 8 p.m. Eastern time, Hanna was moving north at 14 mph, with maximum sustained winds at about 65 mph. The center of the storm was located about 200 miles east-southeast of San Salvador in the Bahamas.

A hurricane warning is in effect for the northwestern Bahamas. A hurricane warning means that hurricane conditions are expected within the warning with the next 24 hours.

Josephine Weakens

Forecasters say Josephine, the tropical storm behind Ike, is weakening. Maximum sustained winds have decreased to around 60 mph. Forecasters said continued weakening is expected Thursday.

At 5 p.m. EDT, the center of Josephine was located about 375 miles west of the Cape Verde Islands.

Yet Another Tropical Depression Forms

In the Pacific, Tropical Storm Karina formed Tuesday south of Mexico's Baja California Peninsula, on a path leading out to sea.

It weakened to a tropical depression Tuesday night and was expected to further weaken over the next few days.

National Hurricane Center said Karina was moving west near 7 mph.