A major earthquake off Mexico’s southern coast killed at least 15 people late on Thursday, with the president saying it was the biggest in a century to hit the country.

The US Geological Survey reported the earthquake’s magnitude as 8.1, but President Enrique Pena Nieto said on Friday it was 8.2, making it the largest in Mexico in 100 years. He also said it was bigger than the one in 1985, when thousands were killed in four Mexican states.

Its epicentre was 123km southwest of the town of Pijijiapan, at a depth of 70km, according to USGS.

“It was a large-scale earthquake,” Pena Nieto said. “It had a bigger magnitude than the one Mexicans knew in 1985.”

The death toll in the massive earthquake has risen to at least 15 people, including two children in Tabasco state.

Patients and family members are seen outside the Institute for Social Security and Services for State Workers (ISSSTE) after the earthquake [Reuters]

Chiapas Governor Manuel Velasco said that three people were killed in San Cristobal, including two women who died when a house and a wall collapsed. He called on people living near the coast to leave their houses as a protective measure.

“There is damage to hospitals that have lost energy,” he said.

“Homes, schools and hospitals have been damaged.”

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Pena Nieto said that serious damage had been caused and that 1 million people initially had been without power following the quake, but that electricity had been restored to 800,000 of them.

“The house moved like chewing gum and the light and internet went out momentarily,” said Rodrigo Soberanes, who lives near San Cristobal de las Casas in Chiapas, a poor, largely indigenous state popular with tourists.

Civil Defense in Chiapas said on its Twitter account that its personnel were in the streets aiding people and warned residents to prepare for aftershocks.

People gather on a street after the earthquake hit Mexico City [Reuters]

The quake was so powerful that frightened residents in Mexico’s distant capital city fled apartment buildings, often in their pajamas, and gathered in groups in the street.

“There have been half a dozen of magnitude five and four aftershocks reported already,” Randy Baldwin, a geophysicist with US Geological Survey’s National Earthquake Information Center, told Al Jazeera.

“There are possibilities that the aftershocks will probably continue for the next several months.”

Tsunami measured

Tsunami waves have been measured off Mexico’s Pacific coast; the Pacific Tsunami Warning Center said waves of 1 metre above the tide level were measured off Salina Cruz.

It was also felt in much of Guatemala, which borders Chiapas.

Mexican officials ordered schools to remain closed on Friday in 10 states, including Mexico City, so officials could inspect for structural damage.

Al Jazeera’s David Mercer, reporting from Mexico City, said there were helicopters hovering over the area monitoring the damage caused by the quake.

“There are not enough reports about the damage caused yet but as day light comes, I am sure they are going to get a better grasp on that information,” he said.

Smaller tsunami waves were observed on the coast or measured by ocean gauges in several other places.

The centre’s forecast said Ecuador, El Salvador and Guatemala could see waves of a meter or less.

No threat was posed to Hawaii and the western and South Pacific.

Lucy Jones, a seismologist in California who works with the US Geological Survey, said such quake was to be expected.

“Off the west coast of Mexico is what’s called the subduction zone, the Pacific Plate is moving under the Mexican peninsula,” she told Associated Press news agency.

“It’s a very flat fault, so it’s a place that has big earthquakes relatively often because of that.”

“There’s likely to be a small tsunami going to the southwest. It’s not going to be coming up and affecting California or Hawaii,” she said.

“For tsunami generation, an 8 is relatively small.”

Source: Al Jazeera and news agencies