QUITO, Ecuador - A strong earthquake shook southern Ecuador and northern Peru Saturday, killing at least a dozen people, trapping others under rubble, and sending rescue teams out into streets littered with debris and fallen power lines.

The U.S. Geological Survey reported an earthquake with a magnitude of about 6.8 that was centered just off the Pacific Coast, about 50 miles (80 kilometers) south of Guayaquil, Ecuador's second-largest city.

Ecuadorian President Guillermo Lasso in a televised address to the nation said the earthquake killed 12 people.

The U.S. Geological Survey reported an earthquake with a magnitude of about 6.8 that was centered just off the Pacific Coast, about 50 miles (80 kilometers) south of Guayaquil, Ecuador's second-largest city.

One victim was a passenger in a vehicle crushed by rubble from a house in the Andean community of Cuenca, according to the Risk Management Secretariat, the South American country's emergency response agency.

In the coastal state of El Oro, three people died and several were trapped under rubble, the agency reported. In the community of Machala, a two-story home collapsed before people could evacuate, a pier gave way, and a building's walls cracked, trapping an unknown number of people.

The agency said firefighters worked to rescue people while the National Police assessed damage, their work made more difficult by downed lines that interrupted telephone and electricity service.

Police talk to people next to the site where a car was crushed by debris after an earthquake shook Cuenca, Ecuador, March 18, 2023.

In Guayaquil, about 170 miles (270 kilometers) southwest of the capital, Quito, authorities reported cracks in buildings and homes, as well as some collapsed walls. Authorities ordered the closure of three vehicular tunnels in Guayaquil, which anchors a metro area of over 3 million people.

Videos shared on social media show people gathered on the streets of Guayaquil and nearby communities. People reported objects falling inside their homes.

One video posted online showed three anchors of a show dart from their studio desk as the set shook. They initially tried to shake it off as a minor quake but soon fled off-camera. One anchor indicated the show would go on a commercial break, while another repeated, 'My God, my God.'

The Marine Museum of Puerto Bolivar, detached from the dock, is partially inundated in water after an earthquake that shook Machala, Ecuador, March 18, 2023.

A report from Ecuador's Adverse Events Monitoring Directorate ruled out a tsunami threat.

The earthquake was also felt in Peru, from its northern border with Ecuador to the central Pacific coast. No deaths or injuries were immediately reported. In the northern region of Tumbes, the old walls of an Army barracks collapsed, authorities said.

Ecuador is particularly prone to earthquakes. In 2016, a quake centered farther north on the Pacific Coast in a more sparsely populated area of the country killed more than 600 people.