United Nations ? Relief crews need helicopters and cash more than anything else to help the estimated 4 million people affected by the earthquake in the disputed Kashmir region, a U.N. official said Thursday.

While exact numbers aren’t clear, it’s believed there are about 50 helicopters ferrying food and supplies to the neediest victims of the quake, but the effort needs about three times that number, said Hansjoerg Strohmeyer, a senior U.N. humanitarian envoy.

“We need a major stepping up of air assets in a dramatic sense,” Strohmeyer said. “We need those who can provide five or 10 helicopters at a time rather than those who can bring in one here and one there.”

U.N. officials are sticking by the official numbers of victims from the quake zone – 25,000 killed and 4 million affected, including 2.5 million left homeless and 1 million in acute need. While they believe they have gotten aid to most of the victims, they still don’t know how many remote villages affected are out there.

Visiting the region earlier Thursday, U.N. Undersecretary General and Emergency Relief Coordinator Jan Egeland said he feared relief workers were “losing the race against the clock” to get to tiny villages accessible only by helicopter.

Shelter needed

People injured by Saturday's earthquake take cover as a helicopter lands bringing more people to a hospital Thursday in the northern Pakistani town of Muzaffarabad. The death toll of the quake in Pakistan was believed to be more than 35,000, with tens of thousands injured.

Strohmeyer said victims are in greatest need of shelter. For the aid community, that means winter tents and mattresses. Pakistan has requested 1 million blankets.

Aid groups are delivering 300 tents and 600 mattresses each day. Another 10,000 tents are in the pipeline. Supplies are pouring into the region at such a pace that traffic jams have begun to form on roads leading into the mountains, Strohmeyer said.

According to Stephanie Bunker, spokeswoman for the U.N. Office for the Coordination of Humanitarian Affairs, some $50 million has been donated in direct response to a U.N. appeal for $272 million. Nations have pledged $176 million directly to Pakistan, but the U.N. expects that some of that money will end up funding U.N. program.

Because of the desperate need for cash, Egeland will seek an international donor’s conference next Thursday in Geneva to raise money, Strohmeyer said. He said the U.N. Office for the Coordination of Humanitarian Affairs had also met with corporations and urged them to donate.

U.N. officials have also renewed their appeal for Middle East nations to contribute to the United Nations appeal. While many of those states contribute bilaterally, they give far less multilaterally.

“The fact remains that our resources are extremely strained at the moment,” Strohmeyer said.