Luis Felipe Puente, the head of the Mexican government's emergency services, said on Twitter that there were no immediate reports of damage. The US Pacific Warning Center announced that it did not expect the quake to trigger a tsunami.

The powerful quake was still felt in the capital, Mexico City. It was one of the more powerful tremors to hit the country since 1985, when a magnitude 8.1 quake killed at least 6,000 people and destroyed many buildings.

The US Geological Survey (USGS) put the epicenter of the quake 37 kilometers (23 miles) north of Tecpan de Galeana, saying it struck at a relatively shallow depth of 48.6 kilometers. Early response data from the USGS and other seismological institutes are often subject to later revision.

The quake was on Mexico's Pacific coastline, close to the beach resort of Acapulco. An Associated Press reporter said that while the quake was strongly felt there, there were no immediate reports of injuries or damage.

msh/mkg (AFP, AP, dpa, Reuters)