Shopkeepers clashed with looters and hungry families huddled under tents waiting for relief supplies yesterday after Pakistan's worst earthquake razed entire villages, buried roads in rubble and knocked out electricity.
The death toll ranged from 20,000 to 30,000 and was expected to rise.
The United Nations warned more than 2.5 million people needed shelter. With landslides blocking roads to many of the worst-hit areas, Pakistan's army was flying food, water and medicine into the disaster zone.
International relief efforts cranked into action, with the US military sending eight helicopters from Afghanistan.
Most of the dead were in Pakistan's mountainous north. India reported more than 750 deaths, and Afghanistan reported four.
In Muzaffarabad, the capital of Pakistan's portion of divided Kashmir, an Associated Press reporter saw shopkeepers scuffle with people trying to break into shuttered businesses. They beat each other with sticks and threw stones, leaving some with bleeding head wounds. No police were in the area.
Residents also said people were looting deserted homes and fuel stations. Survivors lacked food and the city of 600,000 had no water or electricity, amid little sign of official co-ordination of relief in the devastated city. People collected water from a mountain stream.
About 2,000 people huddled around camp fires through the cold night on a football field on the city's university campus, where most buildings have collapsed and hundreds were feared buried in classrooms and dormitories. Soldiers burrowed into the concrete with shovels and iron bars.
"I don't think anybody is alive in this pile of rubble," rescue worker Uzair Khan said. "But we have not lost hope."
On the football field, Mohammed Ullah Khan, aged 50, said a few biscuits handed out by relief workers were his only food for three days. His wife, who suffered a fractured leg, was wrapped in a yellow quilt beside him.
Their three-storey home had collapsed in the quake. His family of ten survived because they were on the top floor, which crashed to the ground.
"My children are now on a hillside, under the open sky, with nothing to eat," he said.
Pakistan's Prime Minister Shaukat Aziz said his country's death toll was 19,396 and was expected to rise.
Senior officials in Pakistan's portion of Kashmir put the death toll much higher. The top elected official in the region, Sardar Sikandar Hayat, said that more than 25,000 people had died there with "countless" injured. Tariq Mahmood, the province's communications minister, put the toll at more than 30,000.
Troops "have not started relief work in remote villages where people are still buried in the rubble, and in some areas nobody is present to organise funerals for the dead," Mahmood said.
The quake was felt across a wide swath of South Asia, with damage spanning at least 250 miles from Jalalabad in Afghanistan to Srinagar in northern Indian territory.
In Geneva, the United Nations urgently appealed for donations, including for at least 200,000 winter tents.