A strong earthquake has rocked Mexico City and Acapulco, although no damage or injuries were immediately reported.
City office workers rushed from swaying buildings, and cars pulled over to the roadside to ride out the tremors.
The quake, at about 1735 local time
(2335GMT), centred in nearby Guerrero state and had a magnitude of 5.3.
About 10,000 people died when Mexico city was hit by a major quake in 1985. The city has implemented some of Latin America's toughest building codes.
Thursday's earthquake was followed by at least one strong aftershock.
The Associated Press news agency said the quake rocked city high rise buildings, sent many people running
from their homes, and caused scattered power cuts.
In Acapulco - not far from the epicentre 25 miles (40 kilometres) east of the
resort of Zihuatanejo - many tourists left their hotels as a precaution.
At the beginning of 2003, 29 people were killed in a 7.9 magnitude earthquake in western Mexico but the capital escaped unscathed.