Lalo Salazar, a newscaster on the Mexican TV network Televisa, was on air at the moment a massive 7.2-magnitude earthquake hit.

He stayed calm as a quake siren sounded while describing the shaking inside the studio.

The tremors were felt across at least half a dozen states and Mexico’s capital.

There were no reports of major damage or casualties.

Some residents said paintings fell off their walls.

Damiana Duran, a Mexico City resident said: “In our office they weren’t allowing people to come out and we were afraid, but now I feel better.”

The US Geological Survey (USGS) initially calculated the quake’s magnitude at 7.5, but later downgraded it to 7.2.

It was centered in the western state of Guerrero, close to the Pacific beach resort, Acapulco.

Friday’s quake occurred along a section of the Pacific Coast known as the Guerrero Seismic Gap, a 200-kilometre section where tectonic plates meet and have been locked, meaning huge amounts of energy are being stored up with potentially devastating effects, said USGS seismologist Gavin Hayes.

A devastating 8.1-magnitude earthquake in 1985 killed thousands of people in Mexico City.

In March 2012, a 7.4-magnitude quake hit Mexico but did not cause major damage.