Magnitude 8.0 earthquake strikes off the southern coast of Mexico

MEXICO CITY- (AP) - A powerful earthquake is shaking Mexico's capital city, causing people to flee swaying buildings and knocking out lights to part of the city.

The U.S. Geological Survey said the earthquake had a magnitude of 8.0 and its epicenter was 165 kilometers (102 miles) west of Tapachula in southern Chiapas state. It had a depth of 35 kilometers, or about 20 miles. It struck around 9:49 p.m. PT Thursday night

Even in distant Mexico City the quake was felt so strongly that frightened residents gathered in the streets in the dark, fearing buildings would collapse.

The Pacific Tsunami Warning Center warned of possible "hazardous" tsunami waves related to the earthquake along some coasts of Mexico, Guatemala, El Salvador, Costa Rica, Nicaragua, Panama, Honduras, and Ecuador.

There were no immediate reports of damage, but Mexico's civil protection agency said Thursday night's quake was the strongest earthquake to hit the country since a devastating 1985 tremor that toppled buildings and killed thousands, Reuters reported.

"I had never been anywhere where the earth moved so much," a witness interviewed by the news wire service said. "At first I laughed, but when the lights went out I didn't know what to do. I nearly fell over," said Luis Carlos Briceno, an architect, 31, who was visiting Mexico City.

This story is developing.