MANAGUA, Nicaragua — The heart of powerful Hurricane Eta began moving ashore in Nicaragua on Tuesday with potentially devastating winds and rains that have already destroyed rooftops and caused rivers to overflow.

The hurricane had sustained winds of 140 mph, according to the U.S. National Hurricane Center.

The eyewall was touching the coast, even if the center of the Category 4 hurricane was still about 20 miles south-southeast of Bilwi, or Puerto Cabezas. It was moving west at about 3 mph.

Guillermo González, director of the country’s emergency management agency, said in a news conference that as Eta began to make landfall there were reports of corrugated metal roofs flying off homes, trees, poles and power lines falling, and rivers rising in the coastal area. So far, there were no reported injuries or deaths, he said.

About 10,000 people were in shelters in Bilwi, the main coastal city in the region, and an equal amount were sheltered in smaller towns across the region, he said. The area had already been lashed with strong winds and heavy rain for hours as the storm’s eye hovered offshore.

Authorities in Nicaragua and Honduras had moved people Monday from outer islands and low-lying areas to shelters. Residents scrambled to shore up their homes, but few structures along Nicaragua’s remote Caribbean coast were built to withstand such force.

Nicaragua’s army moved red-helmeted troops specialized in search and rescue to Bilwi. The navy spent Monday ferrying residents of coastal islands to shelters in Bilwi.