MEXICO CITY, Jan. 2 (Xinhua) -- A 6.5-magnitude earthquake struck southern Mexico's Guerrero state on Friday morning, according to Mexico's National Seismological Service.

There were no immediate reports of casualties or damage.

The agency said the quake occurred at 7:58 a.m. local time (1358 GMT), with the epicenter located about 15 km southwest of San Marcos, at a depth of approximately 10 km.

Earthquake alerts were activated in Mexico City, where the tremor was felt.