Office towers rocked back and forth for several seconds in the center of Mexico City after the quake at 10:36 a.m. (PST) Monday morning and workers evacuated their buildings and gathered in the street.
Mexico City Mayor Marcelo Ebrard said via Twitter that no major damage had been reported by helicopter overflights of the city and public transport and other services were functioning normally.
Interior Secretary Alejandro Poire also said on Twitter that he had received no immediate reports of significant damage.
The U.S. Geological Survey reports a preliminary magnitude of 6.3. Susan Hoover, a seismologist for the USGS, says the epicenter was in southern Mexico near the border of Guerrero and Oaxaca states, very close to the epicenter of a strong quake on March 20. Mexico has been shaken by a series of strong aftershocks since that quake, which killed at least two people and damaged about 13,500 homes near its epicenter.
The quake was one of the strongest in Mexico since an 8.1-magnitude temblor killed an estimated 10,000 people in Mexico City in 1985.
Mexico has been shaken by a series of strong aftershocks since the March 20 quake.
Last month's quake was among the strongest in Mexico since an 8.1-magnitude temblor killed an estimated 10,000 people in Mexico City in 1985. A magnitude-8.0 quake near Manzanillo on Mexico's central Pacific coast killed 51 people in 1995 and a magnitude-7.5 quake killed at least 20 people in the southern state of Oaxaca in 1999.