Pakistani officials called the earthquake that struck Saturday the worst in its history. Rival India, which reported more than 465 dead, offered assistance, reported the Associated Press.
"I have been informed by my department that more than 30,000 people have died in Kashmir," Tariq Mahmmod, communications minister for the Himalayan region, told the AP.
In mountainous Kashmir, the quake flattened dozens of villages and towns, crushing schools and mud-brick houses.
The tremors were felt as far as the capitals of Pakistan, India and Afghanistan and continued for hours afterward.
The U.S. Geological Survey said the earthquake was centered about 60 miles northeast of Islamabad in the forested mountains of Kashmir, the disputed Himalayan territory divided between India and Pakistan.
Pakistan's chief army spokesman Maj. Gen. Shaukat Sultan said the worst hit areas were in Pakistani-controlled Kashmir, including Muzaffarabad, the regional capital, and the towns of Bagh and Rawalakot. The districts of Batagram, Balakot, Mansehra, Abbottabad and Patan in northwestern Pakistan also suffered serious damage, he said.
In the capital Islamabad, Pakistani President Gen. Pervez Musharraf said that the military would provide "all-out help," sending C-130 transport planes and helicopters to devastated areas.
The quake brought down a 10-story apartment building in Islamabad trapping people in the rubble. Some residents were Westerners, the AP reported.
Vijay Bakaya, Jammu-Kashmir state's chief secretary, said teams of doctors and Red Cross volunteers were traveling by road and on foot to remote mountainous areas.
The quake also reached parts of Bangladesh and the American military base in Bagram, Afghanistan, but no casualties or damage were reported.
Dozens of villagers, some with sledgehammers but many without tools, pulled at the debris and carried away bodies in Balakot. Faizan Farooq, a 19-year-old business administration student, said he had heard children under the rubble crying for help immediately after Saturday's disaster, according to the AP.
"Now there's no sign of life," he said Sunday. "We can't do this without the army's help. Nobody has come here to help us."
Helicopters and C-130 transport planes took troops and supplies to damaged areas Sunday. But landslides and damaged roads and bridges were hampering rescue efforts in remote areas.