This post has been updated.
A major 7.6 magnitude earthquake struck 120 miles east of Acapulco on Mexico's Pacific coast, the U.S. Geological Survey reports.
#mexico city airport still swaying from earthquake, a good roller.— Nick Miroff (@NickMiroff) March 20, 2012
The quake was followed by a less powerful aftershock that was also felt in Mexico City.
The Pacific Tsunami Warning Center told Reuters that the quake would not generate a destructive tsunami, but that there could be some local tsunami effects.
Photos and video from the ground: