Mexico City: A strong earthquake has struck off the coast of Mexico, but there were no immediate reports of damages inland.

The US Geological Survey reports a preliminary reading of 6.9 magnitude. It says the temblor was centered 133 kilometers northeast of Guerrero Negro, and hit some 10.3 kilometers below the surface.

It follows a 6.4 magnitude quake, which struck a sparsely populated area in the mountains of western Mexico on Wednesday, and caused tall buildings to sway more than 322 kilometers away in Mexico City.