An earthquake with a preliminary magnitude of 8 has struck off Mexico's southern coast, the United States Geological Survey (USGS) said.

A tsunami warning has been issued for Pacific coasts of several Central American countries.

The USGS said the quake, which struck just before midnight local time on Thursday, had an epicentre 102 miles west of Tapachula in southern Chiapas state not far from Guatemala, and a depth of 22 miles.

The quake was so powerful that frightened residents in Mexico City more than 650 miles away fled apartment buildings and gathered in the street.

The US Tsunami Warning System said waves were possible within the next three hours for Mexico, Guatemala, El Salvador, Costa Rica, Nicaragua, Panama, Honduras and Ecuador.

There was no tsunami threat for the US West Coast.