At least 224 people, including 117 in the capital, were killed by a powerful earthquake that rocked Mexico on Tuesday, the authorities have said, AFP reports.
The dead included at least 21 children crushed beneath a primary school that collapsed on Mexico City's south side during the 7.1-magnitude quake, they said. President Enrique Pena Nieto, who rushed to the site, warned the toll could rise.
The destruction revived horrific memories in Mexico on the anniversary of another massive quake in 1985, the disaster-prone country's deadliest ever.
One of the most gut-wrenching scenes was at the Enrique Rebsamen primary school on Mexico City's south side, whose three floors collapsed into one, trapping students and teachers inside. Twenty-one children and four adults were killed, said deputy education minister Javier Trevino.
"There are 30 children and eight adults still missing. Rescue operations are ongoing," President Enrique Pena Nieto told journalists.
Local media reports said soldiers had located one child alive beneath the ruins. They administered oxygen through a tube, but were so far unable to extract him.
The devastation struck across a swath of central states.
Rescue crews and volunteers in Mexico City -- home to 20 million people -- clawed through the rubble of at least 49 collapsed buildings looking for survivors and bodies.
Local media reported that families were getting WhatsApp messages pleading for help from desperate relatives trapped under debris.
Memories of the devastating 1985 earthquake, which killed at least 10,000 people, surged to the surface on what was meant to be a low-key 32nd anniversary.
Adding to the national sense of vulnerability, the quake also came just 12 days after another that killed nearly 100 people and left more than 200 injured, mainly in the southern states of Oaxaca and Chiapas.
Many in the capital quickly ran for safety outdoors when walls around them swayed and cracked.
"I'm so worried. I can't stop crying. It's the same nightmare as in 1985," Georgina Sanchez, 52, sobbed to AFP in a plaza in the capital.
The quake -- which occurred in the early afternoon, hours after city authorities had conducted an earthquake drill -- caused massive damage in the bustling center of the city.
Scenes of chaos erupted in the quake's aftermath. Traffic jammed to a standstill before blanked-out stop lights, and anxious people ran between vehicles as ambulances tried to make headway, sirens blaring.
In several locations, large crowds of people clambered on buildings that were now piles of stone and tangled metal, trying to pull people out.
Emergency workers held up signs commanding "Silence" so crews could listen for the sounds of any survivors.