A magnitude 5.9 earthquake shook Puerto Rico on Saturday morning, causing a landslide in the southern municipality of Peñuelas.

The quake at 8:54 a.m. local time struck 8 miles southeast of Guanica at a shallow depth of 3 miles, according to the U.S. Geological Survey. It is the most recent in a string of quakes and aftershocks that have left thousands on the island without power and water.

Preliminary reports by the USGS said the quake was a magnitude 6.0 at a depth of 6 miles.

The quake caused outages across the island, including areas of Lares, Adjuntas, Ponce and San German, according to Puerto Rico's Electric Power Authority.

At least 539 buildings were damaged, amounting to losses of $110 million, Gov. Wanda Vázquez said in a press conference Saturday. She said her administration was immediately releasing $2 million to six of the most affected municipalities and putting price freezes on various food products and necessities.

There were no immediate reports of injuries.

In Peñuelas, a landslide sent people running, Telemundo Puerto Rico reported. Video of the landslide shows dust kicking up on a hillside as people below run in different directions. Drone video published by Metro Puerto Rico shows barren mountainside in the aftermath of the slide.

In the nearby town of Guánica, around 500 people taking shelter at a sports complex began to shout and cry when they felt the quake, El Nuevo Dia reported. Many grabbed their cell phones to call relatives.

"I want to leave Puerto Rico ... I'm panicking," Ramona Lugo told the outlet.

Puerto Rico quakes:Many are forced to sleep outside

It was the strongest shake since Tuesday's 6.4 magnitude quake, which killed at least one person and knocked out power to virtually the entire island of more than 3 million.

Many on the island have lost their homes, and thousands remain in shelters.Some are sleeping outside or in open plazas for fear that the buildings could collapse.

"People are afraid," Mayita Melendez, mayor of the southern coastal city of Ponce, Puerto Rico's second largest city, told NPR on Friday.

Just 60% of Ponce residents have power and 88% have water, Melendez said.

Ponce has sustained more than $150 million in damages, according to U.S. Rep. Darren Soto (D-Fla.), who visited the island Saturday. More than 700 people are homeless, and the bridge Guánica is beginning to crack, he said on Twitter.

Scientists say the region has been struck by an "earthquake swarm," which is a series of earthquakes rather than the usual pattern of one dominant earthquake followed by aftershocks.

Puerto Rico earthquakes:950 earthquakes have hit the island so far this year. Why? Blame it on an 'earthquake swarm'

There have been nearly 1,000 earthquakes and aftershocks recorded on Puerto Rico since Dec. 31, according to the USGS. Since December, Puerto Rico has experienced more than 139 earthquakes of magnitudes greater than 3.0, including six that were greater than magnitude 5.0, the USGS said.

Over the next seven days, there is only a 3 percent chance of one or more aftershocks larger than magnitude 6.4, the USGS predicted Friday. There is, however, a high likelihood of aftershocks greater than magnitude 3.0, the USGS said.