The army was slow to respond, and international aid agencies are in some ways just getting started. But here amid the rubble and the rain at the heart of Pakistan's earthquake zone, the zealous foot soldiers of Jamaat ul-Dawa, one of the country's most prominent Islamic extremist groups, are very much in evidence.

On a sloping muddy field near the rushing Neelum River, the group has established a large field hospital complete with X-ray equipment, dental department, makeshift operating theater, and even a tent for visiting journalists. Dispensaries are piled high with donated stocks of antibiotics, painkillers and other medical supplies.

"Even the army people have come over here to get first aid," said Mohammed Ayub, a long-bearded urologist from Lahore who is volunteering at the field hospital. "The casualties and destruction are so much that they are unable to cope."

Jamaat ul-Dawa is no ordinary charity. Founded in 1989 under a different name, it is the parent organization of Lashkar-i-Taiba, one of the largest and best-trained groups fighting Indian forces in the disputed Himalayan province of Kashmir. Lashkar-i-Taiba has been linked by U.S. authorities to al Qaeda and in 2002 was banned by Pakistan's government as a terrorist organization.

Jamaat ul-Dawa is one of several hard-line Islamic groups that have assumed a prominent role in relief operations following the devastating Oct. 8 earthquake in Pakistani-controlled Kashmir and adjacent areas.

Other groups with a visible presence on Saturday in Muzaffarabad, the largest town in the area, were the charitable wing of Jamiat-i-Islami, an Islamic political party with ideological links to the Palestinian militant group Hamas; and the Al-Rasheed Trust, a Karachi-based charity whose U.S. assets were frozen by the Bush administration in 2003 on grounds that it channeled funds to al Qaeda. The group has denied the charge and says it is focused purely on social welfare.

The groups' effective and visible relief work, analysts say, has bolstered their prestige, possibly at the expense of Gen. Pervez Musharraf, Pakistan's president, and the army, whose initial response was widely criticized as slow and disorganized.

"Definitely they will gain," Ershad Mahmud, an analyst on Kashmir at the Institute for Policy Studies in Islamabad, said of Jamaat ul-Dawa. "They have diverted their whole network toward the relief operation."

Pakistani officials say the army has performed admirably given its own devastating losses in the quake, which killed about 450 soldiers. But in an interview Saturday, Interior Minister Aftab Khan Sherpao acknowledged the vital role of Jamaat ul-Dawa and other such groups, calling them "the lifeline of our rescue and relief work."

Jamaat ul-Dawa, he added, "is only involved in extensive charity work, and their footprint now covers almost the entire quake-affected zone in the country." Pakistan placed Jamaat ul-Dawa on its "terrorism watch list" in late 2003.

The government on Saturday raised its estimate of the death toll from the quake to 38,000, with 62,000 injured. The worst damage was in the part of Kashmir controlled by Pakistan; about 1,400 are thought to have died on the Indian side of the province.

With a chilly rain falling on much of the earthquake zone and early snows dusting nearby mountaintops, aid officials voiced growing concern about the welfare of an estimated 2 million people made homeless by the quake. Already there are signs of disease, with 80 cases of diarrhea reported Saturday in the heavily damaged town of Balakot, up tenfold from the day before. Relief officials estimate that 600,000 toilets will be needed to provide adequate sanitation for survivors.

The Jamaat ul-Dawa camp is one of the most visible relief operations in Muzaffarabad, a city of about 70,000 that was largely destroyed by the earthquake and is roughly 50 miles northeast of Islamabad. Situated on the edge of town, the camp is marked with a large hand-painted banner and consists of about 35 canvas tents -- many bearing the name of Jamaat ul-Dawa -- housing medical facilities and more than 100 patients. U.S. helicopters, carrying supplies and the injured, regularly fly over the area.

Equipment and medicine for the camp were salvaged from the group's wrecked hospital in Muzaffarabad and supplemented with donations from across the country, camp officials said.

Besides volunteer doctors and other medical staff, personnel at the camp Saturday included about 20 bearded young men, some wearing camouflage jackets and white headbands emblazoned with the group's name. Ammar Ahmad, an engineering student from Lahore who is volunteering at the camp, said the men were on hand as protection "against ruffians" and were armed with 9mm pistols.

Qazi Kashif, who edits Jamaat ul-Dawa's national magazine and was visiting the camp Saturday, said that the organization no longer had any connection to Lashkar-i-Taiba and that the insurgent group now operates purely on the Indian side of Kashmir. Jamaat ul-Dawa, he said, is "for preaching and public welfare."

But he added, in reference to the Kashmir insurgency, "We are in favor of jihad, no doubt."

Lashkar-i-Taiba operated for years with the blessing of Pakistan's Inter-Services Intelligence Agency, which provided the group with arms and training and helped launch its fighters across the cease-fire line separating Pakistani and Indian forces in Kashmir. It was founded by Hafiz Sayeed, a former Punjab University engineering professor who also started Jamaat ul-Dawa. The two groups shared the same headquarters in the town of Muridke near Lahore.

During the height of the insurgency in the 1990s, Lashkar-i-Taiba fighters assembled openly in Muzaffarabad and nearby training camps. In early 2002, under intense pressure from the United States, Musharraf banned the group and froze its assets. Sayeed was subsequently arrested, although a Pakistani court later ordered his release.

The State Department, in its annual terrorism report, asserts that a top al Qaeda lieutenant was captured at a Lashkar-i-Taiba safe house in March 2002.

Notwithstanding recent progress in peace negotiations with Pakistan, Indian officials have questioned the sincerity of Musharraf's ban and said that Pakistan has yet to dismantle the infrastructure used by insurgent groups on its territory.

Some Pakistani officials seemed to acknowledge as much in the days after the quake. Sikander Hayat Khan, the senior elected official in Pakistani Kashmir, told the private Geo television network that "jihadi organizations had to face massive destruction" near the town of Bagh because of the quake.

And a senior police official from Pakistani Kashmir said that Lashkar-i-Taiba and another prominent separatist group, Hizb-ul-Mujaheddin, "have lost significant assets both in men and material." The official spoke on condition of anonymity because of the sensitivity of the topic.

At the Jamaat ul-Dawa field hospital Saturday, Abdul Majid said he did not know whether the group was involved in violence, nor did he care. A 35-year-old construction worker, he was lying in a leaky tent with a broken leg and back injuries from the earthquake, which killed two of his children, ages 2 and 4.

"Every 10 minutes a doctor or medical attendant comes in to check on me," he said from beneath a heap of blankets. "I have a very high opinion about this organization."

Khan reported from Karachi.

Members of Jamaat ul-Dawa carry two injured Kashmiri boys after they were transferred by boat from a village near Muzaffarabad, Pakistan.Men line up for help at an aid station near Muzaffarabad, which was almost completely destroyed. A man weeps after he was prevented from accompanying a relative aboard a U.S. Black Hawk helicopter for evacuation to Islamabad.