A primary school, a supermarket and a factory were among the 44 buildings destroyed by the 7.1 Magnitude earthquake that rocked Mexico on Tuesday, killing at the last tally more than 220 people.
Thirty of the pupils and 12 adults trapped in the ruins of the school have been declared missing.
Mexican President Enrique Peña Nieto said late on Tuesday more than 20 children and two adults had been found dead at the school, Colegio Enrique Rebsamen, in the neighborhood of Coapa.
Much of the damage in the capital was in the fashionable Condesa and Roma districts near the city centre, according to reports by Reuters.
Rescue crews and ordinary citizens searched through rubble for survivors as night fell on Tuesday on battered cities in central Mexico, including the capital.
The magnitude 7.1 quake toppled dozens of buildings, broke gas mains and sparked fires less than two weeks after another powerful quake killed at least 98 people in southern Mexico.
It also hit just hours after emergency drills marked the anniversary of a temblor that killed thousands in 1985.
Millions of people fled into the streets, where they weathered the violent shaking and desperately sought word about the welfare of family and friends.
Emergency personnel in Mexico City, a metropolitan region of about 20 million people, searched frantically with picks and shovels for survivors beneath the rubble of collapsed buildings.
Emergency personnel and equipment were being deployed across affected areas so that “throughout the night we can continue aiding the population and eventually find people beneath the rubble,” Peña Nieto said in a video posted on Facebook earlier on Tuesday evening.
Rescue workers and soldiers toiled around collapsed buildings where heat-sensing equipment suggested survivors could still be trapped.
Bystanders joined in where they could, clearing debris with their bare hands or whatever tools they could find nearby.
