Mexico hit by second earthquake

People return to their offices after an earthquake in Mexico City (Getty Images)

A strong earthquake struck off the coast of Mexico today.

A preliminary reading of 6.9 magnitude was reported by the US Geological Survey.

It said the earthquake was centred 82 miles north east of Guerrero Negro, and hit some 6.4 miles below the surface.

It followed a 6.4 magnitude quake which struck a sparsely-populated area in the mountains of western Mexico yesterday and caused tall buildings to sway more than 200 miles away in Mexico City.