Two strong earthquakes shook north-central Venezuela on Wednesday afternoon, collapsing buildings in the capital Caracas and prompting scientists to warn of potentially heavy casualties and ‌widespread destruction across the South American country.

The U.S. Geological Survey (USGS) said the first earthquake had a magnitude of 7.2 and its epicentre was west of the community of Morón, located along the country’s Caribbean coast, about 168 kilometres west of Caracas. The quake had a depth of 13 kilometres.

The USGS reported an even larger 7.5-magnitude earthquake just a minute later.

“High casualties and extensive damage are probable, and the disaster is likely widespread,” the USGS said, initially estimating the death toll would most likely range from 10,000 to 100,000.

Authorities did not ​immediately provide official estimates for deaths or injuries.

“We have buildings, homes and houses which ​have collapsed, and we are taking care of things with everything we have available in terms of security, civil assistance,” Interior Minister Diosdado Cabello said on state television. “The fire department, police all have been activated.”

The quakes are among the strongest to strike Venezuela in more than a century.

Tsunami warning cancelled

The U.S. Tsunami Warning System issued ​a tsunami threat ⁠for Puerto Rico and the U.S. and British Virgin Islands following the earthquake, adding that islands off the coast of Venezuela — Aruba, Curaçao and Bonaire — could also be hit by hazardous waves. The warning was withdrawn about an hour later.

Many Venezuelans were at home when ​the quake hit, celebrating a public holiday commemorating an 1821 military victory that secured the country’s independence from ​Spain.

Residents in Caracas rushed to evacuate as the ⁠first quake shook buildings.

Maria Romero, ⁠an 80-year-old pensioner living on ‌the south side of Caracas, said that police helped her evacuate from her building. “This earthquake was horrible, even worse than the one in 1967,” she added.

Many residents in Caracas lost power or internet service right after the quake.

One witness said cracks had formed up the side of their apartment and that glass ​in the entryway had shattered. Power went down shortly after, the witness said.

“Several walls in my building broke open or cracks formed,” a ⁠witness in Valencia, to the west of Caracas, told ⁠Reuters. “As soon ⁠as it stopped [shaking], ​my husband and I evacuated [the building].”

Venezuela’s interior minister said the quake could be felt in several states, adding that the Altamira neighbourhood in Caracas had “alarming situations” with collapsed homes and buildings. Cabello urged people to remain outside as aftershocks could further damage some structures.

He also suggested people were injured in the earthquake, asking motorists to clear the way for ambulances and other emergency vehicles.

“We understand that some people may be desperate, but we are acting according to protocols to activate aid and rescue efforts to help those who need it most,” Cabello said on state television. “Be very careful with children and the elderly; call each other and check that no one has been harmed.”