Many children missing at school

The death toll in the powerful 7.1 magnitude earthquake that rattled Mexico on Tuesday climbed to 250 as rescue workers backed by an army of volunteers on Thursday searched for survivors buried under mounds of rubble, officials said.

The quake turned dozens of buildings in central Mexico into dust and debris, killing at least 250 people, Mexico City Mayor Miguel Angel Mancera told CNN affiliate Foro TV.

Mexican President Enrique Pena Nieto declared three days of national mourning and said the death toll was expected to rise in the coming days as rescue workers combed through tonnes of rubble. “Mexico shares your pain” was posted on the President’s official Twitter account as the period of mourning was announced.

Meanwhile, at a collapsed school, where the bodies of nearly two dozen schoolchildren were found, rescue teams raced against the clock to reach a trapped girl, who had wriggled fingers from the rubble to show she was alive.

Over 30 children missing

The girl, identified only as Frida Sofia, told rescuers there were other students nearby but she could not tell if they were alive. More than 30 children were still unaccounted for.