This article is more than 8 months old

This article is more than 8 months old

A 6.4 magnitude earthquake struck Puerto Rico before dawn on Tuesday and was followed three hours later by an aftershock measuring 6.0. They were the largest in a series of quakes that have struck the US territory in recent days and caused heavy damage in some areas.

Eight people were injured in the city of Ponce, near the epicenter of the quake, Mayor Mayita Meléndez told WAPA television.

Puerto Rico’s power authority said on Twitter one of the country’s main power plants, near the epicenter, had been damaged, but officials expected to restore power to the island later on Tuesday.

The US Geological Survey said the quake hit at 4.24am just south of the island at a shallow depth of 10km. It initially gave the magnitude as 6.6 but later adjusted it. At 7.18am the magnitude-6.0 aftershock hit the same area. People reported strong shaking and staff at a local radio station said on air they were leaving their building

A tsunami alert was issued for Puerto Rico and the US Virgin Islands after the initial quake, but was later canceled.

Albert Rodríguez, who is from the south-west town of Guánica, said tsunami sirens went off before officials canceled the alert. He said there was widespread damage in his neighborhood.

“The road is cracked in the middle and it lifted up,” he said.

The mayor of Guayanilla, Nelson Torres, told NotiUno radio station the church in the public plaza collapsed.

Víctor Huérfano, director of Puerto Rico’s Seismic Network, said it was hard to obtain reports of damage or injuries because communications were down for much of the island. He said officials in Ponce told him there was widespread damage.

“We expect that this will be the largest quake for now,” he said. “The aftershocks will continue for some time.”

Puerto Rico’s governor, Wanda Vásquez, told station Radioisla just before 6am there had been no immediate reports of deaths. She ordered government offices closed for the day and urged citizens to remain calm and not check damage to their homes until daylight.

A 5.8-magnitude quake that struck early on Monday collapsed five homes in the south-west coastal town of Guánica and heavily damaged dozens of others. It also caused small landslides and power outages. The quake was followed by a string of smaller temblors.

The shake collapsed a coastal rock formation that had formed a rounded window, Punta Ventana, that was a popular tourist draw in the town of Guayanilla.

Residents in the south of the island have been terrified to go into their homes for fear that another quake will bring buildings down.

The flurry of quakes in Puerto Rico’s southern region began the night of 28 December. Huérfano told the AP that shallow quakes were occurring along three faults in Puerto Rico’s south-west region: Lajas Valley, Montalva Point and the Guayanilla Canyon.

He said the quakes overall come as the North American plate and the Caribbean plate squeeze Puerto Rico.

One of the largest and most damaging earthquakes to hit Puerto Rico occurred in October 1918, when a magnitude 7.3 quake struck near the island’s north-west coast, unleashing a tsunami and killing 116 people.