People react as Mexican and international rescue teams remove rubble as they search for survivors in a collapsed building after an earthquake, in Mexico City, Mexico September 23, 2017. [Photo/Agencies]

SEARCH FOR SURVIVORS

Roberto Hernandez, 62, leading a group of Mexico's famed "mole" rescue workers at the collapsed office building in Roma, said he believed 30 people were trapped in the rubble, though it was not clear how many were sill alive.

"We can't guarantee there is life but we can guarantee we'll turn over every last stone," Hernandez said.

Tuesday's quake, which flattened dozens of structures in Mexico City, was the second major earthquake to strike the country of 127 million people this month.

A massive 8.1 magnitude quake on Sept 7 off the southwestern coast of Mexico killed around 100 people, most of them in the nearby states of Oaxaca and Chiapas. A series of aftershocks since then have sown panic.

The latest tremor, of 5.7 magnitude, struck on Sunday off the west coast, with its epicenter 80 km (50 miles) south-southwest of Tonala, in Chiapas, the US Geological Survey said. There were no immediate reports of significant damage.

Many more quakes are likely, warned Xyoli Perez Campos, director of Mexico's National Seismological Service.

"We have already recorded more than 4,300 aftershocks," Campos said. "So more aftershocks are to come. What we don't know is if they are going to be of significant magnitude."

President Enrique Pena Nieto visited 12 communities in Mexico state, which borders the capital city, promising that aid would be directed only to those truly affected by the quake and that the government would help rebuild homes and businesses.

"I am publicly promising that ... the affected homes, the families affected and the people in the whole of Joquicingo and the state of Mexico, get back on their feet," he said from that town.

Reuters