MANAGUA (Reuters) - Alma, the first tropical storm of the hurricane season, lost its strength on Friday over Central America, sparing oil platforms in southern Mexico after slamming parts of the region with deadly winds and rain.

The storm struck Nicaragua's Pacific coast on Thursday with winds near 65 mph (100 kph), killing three people as strong gusts toppled trees and power lines and ripped roofs off flimsy homes.

A 7-year-old girl died in Honduras when she was swept away by a current as she tried to cross a raging stream close to the border with Nicaragua, authorities said.

In Nicaragua, one man was killed in the coastal fishing village of Masachapa when he was electrocuted by downed power lines and another died in similar circumstances in the north of the country, the head of the national defense forces said.

The storm was breaking up over the mountains of Central America and was unlikely to keep moving north toward major oil wells and installations in Mexico's Gulf of Mexico, said Lixion Avila, a senior forecaster at Miami's U.S. National Hurricane Center.

People who were evacuated before the storm made landfall along Nicaragua's coast began to return to their homes and water levels in flooded neighborhoods receded as the rains subsided, Nicaraguan authorities said.

Heavy rains fell in various parts of Central America, raising the risk of landslides or more floods, the hurricane center said.

At Tegucigalpa airport in Honduras on Friday, a Salvadoran passenger plane skidded off a runway sodden with rain from Alma, killing five people and injuring 38.

The hurricane center said in an 8 p.m. EDT (0000 GMT) advisory on Friday that heavy rains and floods were possible in the next couple of days over parts of Honduras, El Salvador, Guatemala, Belize and southeastern Mexico.

Hurricane Mitch devastated Central America in 1998, killing 10,000 people. Last year, Hurricane Dean ripped through southern Mexico, closing down platforms that export crude to the United States.

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