Updated 6:39 p.m. ET
ERCIS, Turkey - Distraught Turkish families mourned outside a mosque or sought to identify loved ones among rows of bodies Monday as rescue workers scoured debris for survivors after a 7.2-magnitude quake that killed at least 279 people.
Rescue teams with generator-powered floodlights worked into the night in the worst-hit city of Ercis, where running water and electricity were cut by the quake that rocked eastern Turkey on Sunday. Unnerved by over 200 aftershocks, many residents slept outside their homes, making campfires to ward off the cold, as aid organizations rushed to erect tents for the homeless.
Victims were trapped in mounds of concrete, twisted steel and construction debris after over a hundred buildings in two cities and mud-brick homes in nearby villages pancaked or partially collapsed in Sunday's earthquake. About 80 multistory buildings collapsed in Ercis, a city of 75,000 close to the Iranian border that lies in one of Turkey's most earthquake-prone zones.
Cranes and other heavy equipment lifted slabs of concrete, allowing residents to dig for the missing with shovels.
Deputy Prime Minister Bulent Arinc said the quake killed 279 people and injured 1,300, though search-and-rescue efforts could end as early as Tuesday. Authorities said 10 of the dead were students learning about the Quran at a religious school that collapsed.
Grieving families cried outside an Ercis mosque.
"My nephew, his wife and their child, all three dead. May God protect us from this kind of grief," resident Kursat Lap said.
Bodies were still being pulled from the rubble late Monday. Dozens were placed in body bags or covered by blankets, laid in rows so people could search for their missing relatives.
"It's my grandson's wife. She was stuck underneath rubble," said Mehmet Emin Umac.
Several other men carried a child's body wrapped in a white cloth as weeping family members followed behind.
Afsin Yurdakul, a Turkish-American journalist in Van, Turkey spoke to CBS Evening News anchor Scott Pelley Monday from the site of a collapsed six-story building that housed some 40 families.
Yurdakul said he saw at least six bodies pulled from the rubble of the building Monday. But, "The entire afternoon [rescuers] could hear signs of life," Yurdakul said. "Someone was tapping on the wall, someone was texting a friend to say that she's still alive."
Fewer than 72 hours have passed since the quake, Yurdakul said -- a critical window in which it is still possible to find survivors.
Yalcin Akay was one of those rescued from the collapsed building. He escaped with a leg injury after he called an emergency line on his cell phone and told the operator where he was, Turkey's Anatolia news agency reported. Three others, including two children, were also rescued from the same building in Ercis 20 hours after the quake struck.
Two other survivors were trapped for over 27 hours.
Abdurrahman Antakyali, 20, was brought out of a crumbled Internet cafe after an eight-hour-long joint rescue effort by Turkish and Azerbaijani teams. His father and brother wept with joy as he emerged, Anatolia reported.
Tugba Altinkaynak, 21, had been at a family lunch with 12 other relatives when the temblor hit. Four relatives were pulled out alive earlier but her mother and the others were still missing late Monday. Altinkaynak, who was conscious and covered in dust, was brought out on a stretcher and rushed to an ambulance.
Aid groups scrambled to set up tents, field hospitals and kitchens to help the thousands left homeless or too afraid to re-enter their homes. Many exhausted residents spent a second night outside.
"We stayed outdoors all night, I could not sleep at all, my children, especially the little one, was terrified," said Serpil Bilici of her 6-year-old daughter, Rabia. "I grabbed her and rushed out when the quake hit. We were all screaming."
The bustling, larger city of Van, about 55 miles (90 kilometers) south of Ercis, also sustained substantial damage. Prime Minister Recep Tayyip Erdogan, who inspected the area, said "close to all" the mud-brick homes in surrounding villages had collapsed in the temblor that also rattled parts of Iran and Armenia.
Leaders around the world, including President Barack Obama, conveyed their condolences and offered assistance, but Erdogan said Turkey was able to cope for now. Azerbaijan, Iran and Bulgaria still sent aid, he said.
Among those offering help were Israel, Greece and Armenia, who all have had issues in their relations with Turkey.
The offer from Israel came despite a rift in relations following a 2010 Israeli navy raid on a Gaza-bound aid flotilla that left nine Turks dead. Greece, which has a deep dispute with Turkey over the divided island of Cyprus, also offered to send a special earthquake rescue team.
Turkey and Armenia have no diplomatic ties due to tensions over the Ottoman-era mass killings of Armenians and the conflict in the separatist region of Nagorno-Karabakh.
Turkey lies in one of the world's most active seismic zones and is crossed by numerous fault lines. In 1999, two earthquakes with a magnitude of more than 7 struck northwestern Turkey, killing about 18,000 people.
Istanbul, the country's largest city with more than 12 million people, lies in northwestern Turkey near a major fault line, and experts say tens of thousands could be killed if a major quake struck there.