The temblor struck at 2255 GMT, with the epicentre located around 42 miles (69km) from the Pacific port of Lazaro Cardenas, in Michoacan state, the USGS reported.
Mexico’s seismological service reported no immediate victims or damages and Mexico City mayor Marcelo Ebrard said on his Twitter account that an initial survey of the capital registered no “major damage.”
The international airport and communication networks were operating, he wrote, though cell phone networks were blocked as usually occurs after quakes here.
The quake followed a series of recent temblors in the region.
A powerful 7.4-magnitude earthquake struck southwest Mexico on March 20, killing two people, injuring 13 others and damaging thousands of homes.
Several hundred aftershocks have rocked southwestern and central Mexico since then, including a 6.3-magnitude quake on April 2.
People in Mexico’s crowded capital – with more than 20 million in the metro area – are all too familiar with seismic activity and used to evacuation drills.