ISLAMABAD, Pakistan, AP -A powerful earthquake flattened entire villages of mud-brick homes, triggered landslides and toppled a 10-story apartment building on Saturday, killing more than 18,000 people as it devastated a mountainous swath touching Pakistan, India and Afghanistan.

Pakistan”s private Aaj television reported the Pakistani death toll had jumped to 25,000. But the report, which included casualties in Pakistani-controlled Kashmir, gave no source for its figures and there was no immediate confirmation from Pakistani officials but they have said the toll will rise.

The casualty toll from the 7.6-magnitude tremor rose sharply Sunday as rescuers struggled to dig people from the wreckage, their work made more difficult as rain and hail turned dirt and debris into sticky muck.

Maj. Gen. Shaukat Sultan, Pakistan”s chief army spokesman said early Sunday that more than 18,000 had been killed — 17,000 of them in Pakistani Kashmir, where the quake was centered. Some 41,000 people were injured, he said.

&#34The death toll is gradually rising,&#34 Sultan told The Associated Press. He said authorities had counted the bodies.

For hours, aftershocks rattled an area stretching from Afghanistan across northern Pakistan into India”s portion of the disputed Himalayan region of Kashmir. Hospitals moved quake victims onto lawns, fearing tremors could cause more damage, and many people spent the night in the open.

The earthquake, which struck just before 9 a.m. Saturday, caused buildings to sway for about a minute in the capitals of Afghanistan, Pakistan and India, an area some 625 miles across. Panicked people ran from homes and offices, and communications were cut to many areas.

Most of the devastation occurred in the mountains of northern Pakistan, where the dead included 250 girls crushed at a school and 200 soldiers on duty in the Himalayas.

The U.S. Geological Survey said the quake was centered about 60 miles northeast of the capital, Islamabad, in the forested mountains of Pakistani Kashmir, and was followed by 22 aftershocks, including a 6.2-magnitude temblor.

&#34It is a national tragedy,&#34 Sultan said earlier. &#34This is the worst earthquake in recent times.&#34

In Mansehra, about 90 miles northwest of the Pakistani capital, a shopowner named Haji Fazal Ilahi stood vigil over the body of his 14-year-old daughter, which lay under a sheet on a hospital mattress. He said his wife, another daughter and a brother also died when the family”s house fell.

&#34I could see rocks and homes tumbling down the mountains,&#34 said Ilahi, who was driving to his village of Garlat when the quake struck. &#34When I reached my village, there was nothing left of my home.&#34

India”s government offered condolences and assistance to Pakistan, a longtime rival with which it has been pursuing peace efforts after fighting three wars since independence from British rule in 1947, two of them over Kashmir.

&#34While parts of India have also suffered from this unexpected natural disaster, we are prepared to extend any assistance with rescue and relief which you may deem appropriate,&#34 Indian Prime Minister Manmohan Singh said in a message to Pakistan”s president, Gen. Pervez Musharraf.

India reported at least 340 people killed injured when the quake collapsed 2,700 houses and other buildings in Jammu-Kashmir state. Most of the deaths occurred in the border towns of Uri, Tangdar and Punch and in the city of Srinagar, said B.B. Vyas, the state”s divisional commissioner.

Some 215 Pakistani soldiers died in Pakistan”s portion of Kashmir, Sultan said. On the India side of the border, at least 39 soldiers were killed when their bunkers collapsed, said Col. H. Juneja, an Indian army spokesman.

In Pakistan”s northwestern district of Mansehra, the police chief, Ataullah Khan Wazir, said authorities there pulled the bodies of 250 students from the wreckage of one girls” school in the village of Ghari Habibibullah. Dozens of children were feared killed in other schools.

Mansehra was believed to be a hotbed of Islamic militant activity during the time the Taliban religious militia ruled neighboring Afghanistan. Al-Qaida operatives trained suicide squads at a camp there, Afghan and Pakistani officials told The Associated Press in 2002.

Afghanistan appeared to suffer the least damage. In its east, an 11-year-old girl was crushed to death when a wall in her home collapsed, police official Gafar Khan said.

A U.S. military spokesman, Lt. Col. Jerry O”Hara, said the quake was felt at Bagram, the main American base in Afghanistan, but he had no reports of damage at bases around the country.

The United Nations sent an emergency coordination team to Pakistan.

President Bush offered condolences, and Secretary of State Condoleezza Rice said the United States was ready to help.

&#34At this difficult time, the United States stands with its friends in Pakistan and India, just as they stood with us and offered assistance after Hurricane Katrina,&#34 Rice said in a statement.

In Pakistan, Musharraf and Prime Minister Shaukat Aziz ordered the military to extend &#34all-out help&#34 to quake-hit areas and appealed to the nation to stay calm.

Helicopters and C-130 transport planes took troops and supplies to damaged areas, but landslides and rain hindered rescue efforts.

The only serious damage reported in Pakistan”s capital was the collapse of a 10-story apartment building, where at least 10 people were killed and 126 were injured. Hospital doctors said the dead included an Egyptian diplomat, and the Japanese Foreign Ministry in Tokyo said two Japanese were killed.

A man named Rehmatullah who lived near the apartment building said dust enveloped the wreckage.

&#34I rushed down, and for some time you could not see anything because of the dust. Then we began to look for people in the rubble,&#34 he said. &#34We pulled out one man by cutting off his legs.&#34

&#34It was like hell,&#34 added Nauman Ali, who lives in a nearby building. &#34I was tossed up in my bed and the ceiling fan struck against the roof.&#34

Aided by two large cranes, hundreds of police and soldiers helped remove chunks of concrete, one of which was splattered with blood. One rescue worker said he heard faint cries from people trapped in the rubble.

In Abbotabad, north of Islamabad, dozens of injured quake victims and other patients lay on the lawn of the city hospital as staff with loudspeakers appealed to the public for food and other relief supplies.

One of the injured was an 8-year-old boy, Qadeer, whose father, a farmer named Jehangir, said the only buildings left standing in their village were a mosque and a school. Qadeer lay unconscious, his right leg heavily bandaged.

Authorities laid out dozens of bodies under sheets in a damaged sports stadium in Muzaffarabad.