A very powerful earthquake of magnitude 7.7 on the Richter scale jolted the southern Mexican state of Oaxaca, the US Geological Survey (USGS) said.

Mexico earthquake
Houses were scarred by wide cracks across walls and residents sought to clear debris from the streets.Reuters

At least six people died and several others have been injured as a result of damage to roofs and walls. One of the victims was a male employee of the state oil company Pemex, who fell from a structure during the quake and died from his injuries in the hospital.

The epicentre of the quake, which hit at 10.29 am on Tuesday, June 23, was located 23 km south of La Crucecita, a Pacific Coast village in southern Oaxaca state, the National Seismological Service (SSN) said via Twitter.

A tsunami warning was issued on the Oaxaca coast. The country's seismological service recommended that residents move away from the coastline.

The strong quake was felt in 12 south and central states, and by 2.30 p.m. over 447 aftershocks had been reported. Some structures, including houses, markets, schools, churches and four hospitals at different locations, sustained damage, according to the CNPC.

Houses were scarred by wide cracks across walls and residents sought to clear debris from the streets. As many as 200 houses in the area were damaged, including 30 that were badly impacted, a local official said.

In Mexico City, 32 buildings in the downtown area, near the National Palace, sustained damage to their facades, but only one already condemned building had structural damage, the CNPC said.

Mexico's oil refinery in Salina Cruz, some 143 km from La Crucecita, briefly suspended operations as a precaution, and restarted again.

Mexico is located above various fault lines. In the past 35 years there were several powerful quakes in the southern and central parts of the country, which caused wide-scale destruction and heavy casualties.

(With agency inputs)