MEXICO CITY -- A powerful earthquake shook central Mexico Tuesday, collapsing buildings in plumes of dust and killing at least 226 people. One report put the number as high as 248. Thousands fled into the streets in panic, and many stayed to help rescue those trapped.

Dozens of buildings tumbled into mounds of rubble or were severely damaged in densely populated parts of Mexico City and nearby states. Mayor Miguel Angel Mancera said buildings fell at 44 places in the capital alone as high-rises across the city swayed sickeningly.

Hours after the magnitude 7.1 quake, rescue workers were still clawing through the wreckage of a primary school that partly collapsed in the city's south looking for any children who might be trapped. Some relatives said they had received Whatsapp message from two girls inside.

President Enrique Pena Nieto visited the school late Tuesday and said 22 bodies had been recovered there, two of them adults. He added in comments broadcast online by Financiero TV that 30 children and eight adults were still reported missing. Rescuers were continuing their search and pausing to listen for voices from the rubble.

The quake sent people throughout the city fleeing from homes and offices, and many people remained in the streets for hours, fearful of returning to the structures.

Alarms blared and traffic stopped around the Angel of Independence monument on the iconic Reforma Avenue.

Electricity and cellphone service was interrupted in many areas and traffic was snarled as signal lights went dark.

The U.S. Geological Survey said the magnitude 7.1 quake hit at 1:14 p.m. local time (2:15 p.m. EDT) and was centered near the Puebla state town of Raboso, about 76 miles southeast of Mexico City.

The quake was the deadliest in Mexico since a 1985 temblor on the same date killed thousands. It came less than two weeks after another powerful quake caused 90 deaths in the country's south.

exico's civil defense agency said the death toll had risen to 226. The official Twitter feed of agency head Luis Felipe Puente said early Wednesday that 117 people were confirmed dead in Mexico City, and 55 died in Morelos state, which is just south of the capital. It said 39 are dead in Puebla state, where the quake was centered.

Twelve people died in Mexico State, which surrounds the capital, and three in Guerrero state. The count did not include one death reported by officials in Oaxaca state.

The federal government declared a state of disaster in Mexico City, freeing up emergency funds. President Enrique Pena Nieto said he had ordered all hospitals to open their doors to the injured.

Mancera, the Mexico City mayor, said 50 to 60 people were rescued alive by citizens and emergency workers in the capital. Authorities said at least 70 people in the capital had been hospitalized for injuries.

The federal interior minister, Miguel Angel Osorio Chong, said authorities had reports of people possibly still being trapped in collapsed buildings. He said search efforts were slow because of the fragility of rubble.

"It has to be done very carefully," he said, and "time is against us."

At one site, reporters saw onlookers cheer as a woman was pulled from the rubble. Rescuers immediately called for silence so they could listen for others who might be trapped.

Mariana Morales, a 26-year-old nutritionist, was one of many who spontaneously participated in rescue efforts.

She wore a paper face mask and her hands were still dusty from having joined a rescue brigade to clear rubble from a building that fell in a cloud of dust before her eyes, about 15 minutes after the quake.

Morales said she was in a taxi when the quake struck, and she got out and sat on a sidewalk to try to recover from the scare. Then, just a few yards away, the three-story building fell.

A dust-covered Carlos Mendoza, 30, said that he and other volunteers had been able to pull two people alive from the ruins of a collapsed apartment building after three hours of effort.

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