A major 7.4 magnitude earthquake struck Mexico on Friday, triggering a tsunami threat for around one million people.

The seismic activity struck near the coast of Chiapas, Mexico's southernmost state, bordering Guatemala to the east, the Pacific Ocean to the southwest, and the Mexican states of Oaxaca, Veracruz and Tabasco.

A tsunami threat was issued shortly after the earthquake struck at 10.48am ET, warning that the seismic event could generate dangerous waves capable of inundating nearby coastlines. 

People living in coastal areas are told to prepare for potential flooding, strong ocean currents or massive waves.

The National Tsunami Warning Center noted that there is no tsunami danger for the US West Coast, British Columbia or Alaska.

Sirens were heard blaring through Chiapas as people stood outside, reeling from what had just occurred.

Experts warned that shaking intensity can vary depending on local terrain and the type of buildings in the area, but shallow earthquakes are often felt across a much wider region. They also cautioned that aftershocks are likely in the hours and days ahead.

The earthquake-prone region has experienced 22 quakes over the past 30 days, making this the strongest recorded during that period.

Locals in the area are being told to drop, cover and hold on if indoors, and then check on neighbors to ensure they are safe. 

Eyewitnesses told Reuters news agency that in Guatemala and El Salvador, 'buildings shook.' 

One local said on X: 'It felt like an earthquake in El Salvador, guys, soft and swaying in the city of Usulután. Santa Tecla was strong.' 

In Mexico City, more than 500 miles away from the epicenter, people felt their homes shake and saw lights blinking. 

It remains unclear if there was any significant damage or injuries caused by the earthquake. 

Salomón Jara Cruz, the governor of the southern Mexican state of Oaxaca, has urged citizens to 'remain calm'.

He added the earthquake was felt with 'moderate intensity but said 'no significant damage' has been reported.

'To date, no significant damage has been reported. Citizens are urged to remain calm, follow the authorities' recommendations, and stay informed solely through official channels,' he wrote on X.

However, those living in the region said they never received alerts about the earthquake.

One person shared on X: 'The 'presidential alert' is useless; it never even rang.' 

'Why didn't the seismic alert sound, and last time in Oaxaca nothing even happened, but here it did sound,' another shared.

The epicenter sits along the Pacific Ring of Fire, a 25,000-mile horseshoe-shaped belt around the Pacific Ocean.

It is the most seismically and volcanically active zone in the world, home to about 75 percent of Earth's dormant and active volcanoes and generating roughly 90 percent of all global earthquakes