Mexico City: People may be trapped in 10 buildings after earthquake

People could be alive in 10 collapsed buildings in Mexico City following Tuesday's devastating earthquake, the country's president has said.

Emergency services said the total number of dead had risen to 286. More than half - 148 - lost their lives in the capital.

All the pupils at a school in Mexico City that collapsed after the 7.1 magnitude quake have been accounted for, the country's navy has said.

Earlier reports suggested that a 12-year-old girl was trapped in the rubble and had been able to communicate with rescuers.

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But in an update, Navy Assistant Secretary Angel Enrique Sarmiento said that while there were traces of blood and other signs suggesting someone might still be alive, it was probably a school worker.

Mr Sarmiento said 19 children and six adults died in the school collapse, and that 11 children were rescued.

"We have done an accounting with school officials and we are certain that all the children either died, unfortunately, are in hospitals or are safe at their homes," he said.

Rescuers are continuing to search for survivors using thermal scanners and cameras to locate bodies, and ropes, pry bars and sledge-hammers to break up and move rubble.

Emergency services have been joined by Mexico's "mole" rescue workers, who formed as a volunteer search and rescue group in the aftermath of the devastating quake that struck Mexico City in 1985.

They have worked at disaster sites across the world including the 2001 attacks on the World Trade Center in New York.

President Enrique Pena Nieto has declared three days of national mourning, but said the race to pull out survivors was still the priority.

"Every minute counts to save lives," he tweeted.

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The quake was centred near Raboso in Puebla state, 76 miles (123km) southeast of Mexico City, but the shaking in the capital was almost as intense.

When it struck, panicked workers fled from office buildings and clouds of dust rose up from the crumbling facades of damaged buildings.

The earthquake came less than two weeks after an 8.1 magnitude tremor in southern Mexico killed at least 98 people.

Amid the latest quake, the Popocatepetl volcano near the capital had a small eruption, flattening a church on its southern slopes and killing 15 people attending a mass.