Aftershocks rattled Central America on Tuesday after a powerful 7.3-magnitude earthquake struck offshore, killing one person, damaging homes and scaring people into spending the night outside.

The rumble was felt from southern Mexico to Panama when the quake shook the region late Monday, briefly triggering a tsunami alert.

El Salvador was hardest hit, with officials reporting 14 wrecked homes, damage to a hospital and power outages.

"It was strong when it started to rumble, and it would not stop. My family just prayed and asked God for it to stop," Maria Etelvina Deras, a resident of Usulutan, 110 kilometers (68 miles) southeast of San Salvador, told YSKL radio.

In San Miguel, 135 kilometers (84 miles) east of San Salvador, a man was killed when an electrical pylon fell on him, the city's mayor Wilfredo Salgado told the radio station.

Jorge Melendez, El Salvador's civil protection chief, said the damage was still being assessed nationwide.

People slept outdoors in the most affected areas as 11 aftershocks rattled nerves, including a 4.1-magnitude temblor, according to Salvadoran authorities.

"All I could see was that things in the house were moving, and my wife grabbed me and took me out to the courtyard of the house and we waited for it to stop. It was ugly," said Ruben Aguirre in Zacatecoluca, another town southeast of the capital.

At least 17 aftershocks shook Nicaragua, including a 5.0-magnitude earthquake, according to the Nicaraguan Territorial Studies Institute.

In Nicaragua, minor damage was reported in some 2,000 homes made of adobe or wood, while some hospitals were evacuated as a precaution.

The quake hit in the Pacific Ocean, 170 kilometers (105 miles) southeast of the capital San Salvador, at a depth of 70 kilometers (44 miles), the US Geological Survey said.

- 'Like a rocking boat'-

The US Pacific Tsunami Warning Center quickly issued a warning for coastal areas located within 300 kilometers (190 miles) of the epicenter, but lifted the alert minutes later.

The tremor was felt in the Nicaraguan capital Managua and other cities, prompting people to flee into the street and onto patios while electricity went out momentarily.

"It was like being rocked in a boat," said Lorena Galo, who lives in Managua.

Coastal residents fled their homes but began to return after the danger subsided on Tuesday.

Still, Nicaraguan President Daniel Ortega declared a preventive state of alert along the coast due to aftershocks and schools were closed nationwide.

Electricity and phone service in some areas of Nicaragua were cut off.

In the port city of Corinto, people fled inland in cars or on foot, Radio Ya reported.

The quake was also felt strongly in Honduras and Guatemala, but there were no reports of casualties or major damage.

A 5.3 magnitude aftershock was felt in Costa Rica.