Pakistan's army flew a team of geologists to an isolated northwestern valley Tuesday to investigate reports by anxious villagers of possible volcanic activity in the quake-shattered Himalayan foothills, a government official said.

An official from Pakistan's meteorological department said there was little chance of volcanic activity as the country has no recent history of eruptions.

Nevertheless, a two-man team left for the Alai Valley to investigate the villagers' claim, said chief army spokesman Maj. Gen. Shaukat Sultan (search). The valley is at an elevation of about 6,000 feet, surrounded by mountains as high as 10,000 feet.

Army helicopters flew over the rugged region of North West Frontier Province (search) on Monday and found no immediate signs of an eruption, Sultan said.

Sultan speculated that aftershocks from the massive Oct. 8 quake and subsequent landslides kicking up dust could cause the terrified villagers to mistakenly believe that volcanic activity is occurring.

Government officials have been eager to dispel rumors among local residents — and even those in the capital of Islamabad — that another major quake was imminent.

If the team finds evidence of volcanic activity, Sultan said there would be evacuations.

An estimated 3.3 million people have already been left homeless by the quake, which killed about 80,000 people.

A huge international relief effort has been mounted for the victims, but fears remain for vulnerable communities in distant mountains with the harsh Himalayan winter closing in. Temperatures on Tuesday dropped to 30 degrees in the mountains, dangerous weather for those left outdoors.

Cloudy weather Tuesday raised concern about rain in the coming days. But Maj. Farooq Nasir, army spokesman in Muzaffarabad (search), said helicopter relief flights were still operating.

U.N. Secretary-General Kofi Annan (search) invited ministers to attend a high-level donor conference in Geneva on Wednesday to mobilize additional financial support. Despite fresh appeals and warnings of a second wave of deaths, the United Nations said Monday it has received less than 30 percent of the $312 million it needs to help the victims. Pakistan has said rebuilding the area will cost $5 billion.

Indian soldiers have set up a relief camp for Pakistani quake victims along the Line of Control dividing Kashmir, although it remains empty as the two countries try to broker a deal to allow people to cross the militarized frontier.

If they agree, it would be the first time in nearly six decades that Kashmiris would be allowed to walk across the frontier of the region, divided since 1948.

A visit to the camp in Gulpur on Tuesday revealed two medical tents equipped to carry out minor surgery and shelters for about 100 people along with bathrooms.

The camp is part of a plan India announced Saturday to set up three relief centers along the Line of Control, said army spokesman in Kashmir Lt. Col. V.K. Batra.

Pakistan followed India's announcement by proposing five camps be set up. The opening of the camps was delayed because they could not reach a compromise on their competing proposals. Officials from both sides were to meet Saturday in Pakistan, Indian Foreign Ministry spokesman Navtej Sarna said in New Delhi.

A U.S. Army field hospital unit, with more than 130 staff, started treated patients on Tuesday in Muzaffarabad, the capital of Pakistani-controlled Kashmir. Washington hopes the mission will generate goodwill among Pakistanis.

Officials say it is the eighth mobile hospital to be set up in the ruined city, and only two patients were waiting when it opened Tuesday morning. One was a 3-year-old girl with a broken thigh from her home collapsing on her. The other, an 8-year-old boy, had been caught in a collapsed school and had a bad gash on his ankle.

U.S. officials say they are eager to show Pakistan — a major ally in the war on terrorism — that the United States is here in its hour of need. Its helicopters — mostly heavy-lifting Chinooks — are key to the air relief effort.

A second hospital unit is on its way from the U.S. base at Okinawa, Japan, said Rear Adm. Michael LeFever, director of the U.S. Disaster Assistance Center in Pakistan. That team, along with more helicopter and maintenance personnel, will bring the total U.S. military presence there to more than 1,000.

Despite the chaos in the quake zone, there have been few known cases of looting or anarchy. But police in quake-hit Mansehra district, north of Islamabad, said Tuesday they had arrested 350-400 people in the past two weeks for stealing relief supplies or lining up to receive aid more than once.

The arrests were made in a number of damaged towns, local police chief Yamin Khan said.

"We want to ensure that only those who need the aid get it," he said.