Mexico was shaken Monday afternoon by a strong apparent aftershock from a powerful earthquake late last month.
Office towers rocked back and forth for several seconds in the center of Mexico City 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 a helicopter overflight of the city.
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 nearly two weeks ago.
At least two people died as a result of that quake and hundreds of homes were damaged 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.