MEXICO CITY - A powerful earthquake measuring 6.4 on the Richter scale jolted southwestern Mexico's Guerrero state on Thursday, the Mexico National Seismological Service said.

The epicenter, with a depth of 47 km, was initially determined to be at 19 km east of Altamirano city of the Guerrero state.

The quake was felt strongly in the Mexico City.

In a report monitored here, the US Geological Survey put the magnitude at 6.0 on the Richter scale. It said the quake struck at 09:20:23 GMT on Thursday.

The epicenter, was initially determined to be at 18.4069 degrees north latitude and 100.3734 degrees west longitude, according to the US Geological Survey.