A magnitude 7.2 earthquake hit Mexico City on Friday morning. Buildings shook for at least 30 seconds and there was widespread panic.
The US Geological Survey said the quake was registered at a depth of 24km. The epicentre was in the western state of Guerrero, near the seaside resort of Acapulco.
It was felt as far away as Puebla and Tlaxcala states in central Mexico.
The quake occurred at 7.27am local time on Friday. There are no reports of casualties or significant damage, but residents across the capital fled their homes as the tremor began.
At least 10,000 people were killed in the city by a magnitude 8.1 earthquake in 1985.