A STRONG, LONG  7.6-magnitude earthquake swayed buildings in Mexico City and sent frightened workers and residents into the streets in the past two hours.

The quake, with an epicentre in Guerrero state was followed by an aftershock that shook central southern Mexico.

The US Geological Survey set the intensity of the first quake at 7.6 and said the epicentre was 11 miles underground and was felt strongly in Oaxaca. Mexico’s National Seismological Survey said the tremblor had an epicentre southwest of Ometepec in Guerrero state.

Mexico City Mayor Marcelo Ebrard’s Twitter account said the water system and other “strategic services” were not experiencing problems and no damage was reported in the central or northern zones of the city.

But frightened workers and residents poured into the streets of the capital just minutes after noon local time (6pm Irish time). Buildings were evacuated and residents gathered at the Angel de la Independencia square.

Through his Twitter account, President Felipe Calderon said there were no immediate reports of damage. Telephone services, however, were down in the city and throughout the area where the quake was felt.

BBC reports that mobile phone networks have also been impacted.

-Additional reporting by AP