A powerful 6.7 magnitude earthquake hit Guerrero state in southwest Mexico, rattling buildings as far away as the capital Mexico City.

Reuters reporters in Mexico City said the earthquake seemed to go on for an unusually long period. There were no immediate reports of damage but residents ran out of buildings and gathered in the streets outside.

It felt very strong. All the emergency services have been activated, Marcelo Ebrard, Mexico City's mayor, said on his Twitter account.

The earthquake struck at 7:47 p.m. (0147 GMT Sunday) in the southwestern state of Guerrero and was 40 miles deep, the U.S. Geological Survey reported.

I was on the fifth floor when I felt it. It was a very strong shake, said Mexico City resident Amor Lajud. My dogs started barking. I just rushed out for the exit and got out.

Lajud lives in an apartment building in the Condesa neighborhood of Mexico City, which suffered serious damage in a devastating 1985 earthquake.

The Pacific Tsunami Warning Center said a destructive tsunami was not generated by the quake.