Mexico was shaken Monday afternoon by a strong apparent aftershock from a powerful earthquake late last month.
Officials said there were no immediate reports of serious damage or injuries from the quake, which had an initial magnitude of 6.3.
Office towers rocked back and forth for several seconds in the centre of Mexico City after the quake at 12:36 p.m. (1736 GMT) Monday afternoon 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 reported a preliminary magnitude of 6.3 for Monday's aftershock and said 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.
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.