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Rescuers in central Italy raced to pull residents buried beneath rubble after a 6.2-magnitude earthquake rocked a string of small towns early Wednesday, killing at least 159 people and wounding 368 others.

Italy's defense ministry mobilized the army in search of survivors, using bare hands, heavy equipment and sniffer dogs to sift through the waste and wriggle people free. Emergency units set up makeshift hospitals and tent cities to care for the injured — many left dazed by the scenes of destruction and desperate to find loved ones feared among the dead.

The temblor hit at 3:36 a.m. local time (9:36 p.m. ET Tuesday) near Norcia, 50 miles southeast of Perugia, and was felt more than 100 miles away in Rome.

Several large aftershocks followed amid dramatic scenes of rescue and cries for help.

An 10-year-old girl was pulled alive from the rubble after nightfall Wednesday in the damaged town of Pescara del Tronto, The Associated Press reported. Two women ran up the street yelling, "She's alive!"

Chief firefighter Danilo Dionesei confirmed to the AP that the girl was pulled out alive and was taken to a nearby hospital. He didn't immediately give details about her condition.

Throughout the day, stunned residents in the worst-affected towns of Accumoli and Amatrice picked through ruins.

The center of Amatrice was devastated, with entire palazzos razed to the ground. Aerial images from the fire department showed whole streets flattened. The hard-hit hilltop city was set to host a food festival later this week, and it was already anticipating tourists flooding into the area.

"There are people under the rubble," Mayor Sergio Pirozzi told the state-run broadcaster RAI. "The town isn't here anymore."

PHOTOS: Crews Rescue Burried Survivors After Italy Earthquake

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Aftershocks were still occurring in the town as late as 1 p.m. local time. More than 40 were felt throughout the region.

Prime Minister Matteo Renzi said Italians "show their best side in difficult moments," telling reporters: "We must continue to work and to dig through the debris in order to save human lives and give hope to all those involved in the area."

President Sergio Mattarella described the tragedy as a "moment of pain" for the country, while Pope Francis led pilgrims in prayer. The Vatican sent a six-man team from its fire squad to assist in the rescue operations.

"Hearing the mayor of Amatrice say that the town no longer exists, and learning that there are children among the dead, I am deeply saddened," the pope said in remarks at St. Peter's Square in the Vatican.

About 50 of the dead were in Amatrice alone, a police officer told NBC News.

Francesca Maffini, a spokeswoman for Italy's civil protection agency, said that residents in Amatrice were "distraught" and that schools were being used as makeshift shelters for the many who were displaced.

"We flew to Amatrice from Rome in a helicopter, so I saw it from the air," she told NBC News. "There are a lot of historical buildings that are destroyed. It's really bad."

Residents, rescuers and even priests used shovels and their hands to dig out survivors in the devastated town. A firefighter said as many as 70 people were buried in the ruins.

The town's hospital was badly damaged, and patients were moved into the streets.

Maffini added that at least 10 people were killed in the town of Arquata.

The epicenter was about five miles from Norcia in central Italy, but tremors were felt as far away as the country's coasts. NBC News

The mayor of Accumoli said at least seven people had died there, and rescue crews were frantically searching for four others after three people were found alive under the debris.

"We came out to the piazza, and it looked like 'Dante's Inferno,'" Agostino Severo, a Rome resident visiting the damaged town of Illica, told the AP. "People crying for help, help."

Authorities said the quake was similar in scale to the devastating 2009 temblor in nearby L'Aquila, which killed more than 300 people. They urged Italians to give blood and donate blankets, medicine and water.

Roads were blocked in several areas of the mountainous hamlets, severely hampering efforts to assess the damage and deploy rescue operations. A key road bridge over the Castellano River leading to Amatrice was declared unsafe.

"We need chain saws, shears to cut iron bars and jacks to remove beams: everything, we need everything," Andrea Gentili, a civil protection worker, told the AP.

Infrastructure Minister Graziano Del Rio and Fabrizio Curcio, the head of Italy's Civil Protection Department, were on their way to reach the affected areas, the government said.

Curcio said at a news conference that the region is popular with visitors escaping the August heat of Rome, with more people than at other times of the year.

A man is pulled out of the rubble following an earthquake Wednesday in Amatrice, Italy. Massimo Percossi / AP

Facebook activated its safety check-in service for the affected area Wednesday morning, and the U.S. State Department urged all American citizens in the region to check in with friends and family to let them know they were safe.

Italy sits on two fault lines, making it one of the most seismically active countries in Europe.

Wednesday's quake occurred along a fault in the central Apennine Mountains, which span Italy from the Gulf of Taranto in the south to the southern edge of the Po River basin in the north, the USGS said.

Patrick Defelice, 55, of New York, who was visiting on vacation, told NBC News he and his wife were awakened at 3:30 a.m. "out of dead sleep" in Assisi, near Perugia.

"The building was shaking pretty good," Defelice said.

The quake woke people up in Rome, where lights swayed and car alarms went off.

About 100 miles northeast of Rome in the town of Ceseli, Lina Mercantini also felt the temblor.

"It was so strong," she said. "It seemed the bed was walking across the room by itself with us on it."