Two strong quakes struck off the southern coast of Cuba on Sunday, damaging homes on the coast, officials said.

The larger, 6.8-magnitude quake happened at 11:49 a.m. Cuba time about 24 miles south of Bartolomé Masó, Cuba, data from the United States Geological Survey shows. It shook the island about an hour after a quake in the same area with a magnitude of 5.9.

The quakes damaged homes and powerlines and caused landslides in the coastal provinces of Santiago de Cuba and Granma, Cuban President Miguel Díaz-Canel Bermúdez said on X. He urged people in those areas to stay outside in open spaces. “The first and most essential thing is to save lives,” Mr. Díaz-Canel said.

People at the U.S. Navy base at Guantanamo Bay felt at least three tremors or tremblers on Sunday afternoon. No injuries or damages were reported there.

As seismologists review available data, they may revise the earthquakes’ reported magnitudes. Additional information collected may also prompt U.S.G.S. scientists to update the shake-severity maps.

Aftershocks in the region

An aftershock is usually a smaller earthquake that follows a larger one in the same general area. Aftershocks are typically minor adjustments along the portion of a fault that slipped at the time of the initial earthquake.

Aftershocks can occur days, weeks or even years after the first earthquake. These events can be of equal or larger magnitude to the initial earthquake, and they can continue to affect already damaged locations.

Carol Rosenberg reported from Guantanamo Bay, Cuba. Frances Robles contributed reporting.