Mexico earthquake is strongest to hit country in 100 years, President Enrique Peña Nieto says

A magnitude-8.4 earthquake off Mexico's southern coast is the strongest to hit the country in 100 years, President Enrique Peña Nieto has said.

At least five people have died in the tremor, the Mexican leader confirmed. Major damage has been caused and that 1 million initially had been without power following the quake, but that electricity had been restored to 800,000 of them, he said.

There have been 62 aftershocks and it's possible one as strong as 7.2 could hit, he warned.

The U.S. Geological Survey said the quake had a magnitude of 8.1. It hit off the coast of southern Mexico, toppling houses in Chiapas state, causing buildings to sway violently as far away as the country's distant capital and setting off a tsunami warning.

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

He said 62 aftershocks followed the quake and it was possible one as strong as 7.2 could hit in the next 24 hours.

Mr Pena Nieto also said serious damage had been caused and that one million customers had initially been left without power following the quake, but that electricity had since been restored to 800,000 of them.

The USGS said the quake struck at 11.49pm local time on Thursday and its epicentre was 102 miles (165km) west of Tapachula in Chiapas, not far from Guatemala. It had a depth of 43.3 miles (69.7km).

The quake was so strong that it caused buildings to sway violently in Mexico's capital, more than 650 miles (1,000km) away.

Residents fled buildings, many in their pyjamas, and gathered in frightened groups in the street. Some neighbourhoods remained in darkness after electricity was knocked out.

"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.

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

"There is damage to hospitals that have lost energy," he said. "Homes, schools and hospitals have been damaged."

Tabasco Governor Arturo Nunez said two children died in his state. One was killed when a wall collapsed, and the other was a baby who died in a children's hospital which lost electricity, cutting off the infant's ventilator.

The Pacific Tsunami Warning Centre said waves of 3ft (1m) above the tide level were measured off Salina Cruz, Mexico.

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 3ft (1m) or less. No threat was posed to Hawaii and the western and South Pacific.

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

In neighbouring Guatemala, President Jimmy Morales spoke on national television to call for calm while emergency crews checked for damage.

"We have reports of some damage and the death of one person, even though we still don't have details," he said. He added that the unconfirmed death occurred in San Marcos state near the border with Mexico.

Lucy Jones, a seismologist in California who works with the US Geological Survey, said such a 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 said. "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 south-west. It's not going to be coming up and affecting California or Hawaii. For tsunami generation, an 8 is relatively small."

Additional reporting by agencies