MEXICO CITY: A powerful 7.4 magnitude earthquake struck southern Mexico on Tuesday, triggering a tsunami warning along Central America's Pacific coast and as far south as Ecuador.

The epicenter was near Crucecita, in the southeastern state of Oaxaca, but the shock wave was felt as far away as Mexico City, some 700 kilometers (430 miles) distant, where it sent frightened residents rushing into the streets.

The US Geological Survey reported that the quake struck with a magnitude of 7.4, at a depth of 23 kilometers. After initially publishing a reading of 7.1, the Mexican Seismological Service revised its figure to 7.5.

The US Pacific Tsunami warning center said hazardous waves as high as three meters could strike anywhere within 1,000 kilometers of the quake's epicenter, affecting the Pacific coast of Mexico and Central and South America.

The highest waves, of one to three meters, are expected along Mexico's southern coast near where the quake hit hardest, the center said.

Waves of up to one meter could strike the coast of Ecuador, and smaller waves under a half-meter could be seen in Central American countries as well as Hawaii and Peru.