The U.N. relief agency in Geneva has called efforts to help victims of Pakistan's earthquake a logistical nightmare - worse than after last year's Indian Ocean tsunami. The agency issued an urgent appeal for more donations.

Two weeks after a powerful earthquake hit the Kashmir region of southeast Asia, the United Nations estimates that about three million people are without shelter in Pakistan, and another 67,000 people are seriously injured. U.N. Emergency Relief Coordinator Jan Egeland told reporters in Geneva that aid has not yet reached at least half a million people in the Pakistan-held portion of Kashmir.

U.N. Office for the Coordination of Humanitarian Affairs Spokeswoman Elisabeth Byrs summed up the situation as a "logistical nightmare." The United Nations needs at least $312 million to aid the earthquake victims, she says - a figure that will likely be adjusted in the coming weeks.

The international community has only pledged $86 million through the United Nations. Many foreign donors, Ms, Byrs says, are just too stretched to contribute more to the earthquake relief effort.

"I think the international community is facing so many disasters: facing African crises, tsunami, hurricane Katrina, all the hurricane season and the coffers are empty," said Elisabeth Byrs. "So we urgently need to find new donor countries. For instance, the Gulf countries have to do more - China, Japan, some Latin American countries - and we have to find money and additional donors."

The U.N.'s Egeland says tens of thousands of people could die if aid does not reach them in a timely manner. In a few weeks, cold weather and snowfall will likely arrive in the Kashmir region, risking a cut off in aid delivery.

A donor meeting is scheduled for next Wednesday in Geneva, and the United Nations hopes it will lead to fresh commitments of earthquake-related aid.