Japanese aid groups participating in the largest international disaster relief operation in Southern Asia said Tuesday that efforts to help the survivors are falling short despite the unprecedented level of support and donations.

"We have received a lot of public responses, probably because the disaster occurred during the yearend and New Year's holidays," said Kazuyoshi Misawa, a spokesman for Tokyo-based aid group Peace Winds Japan. "But the scale of damage is enormous and we still need to deliver more supplies."

Peace Winds is delivering medicine and food to Meulaboh, a town on the western coast of the Indonesian island of Sumatra that took the brunt of the tsunamis triggered by the Dec. 26 magnitude 9 temblor off the island.

Misawa said his group has received about 3 million yen in donations but still needs more medicine, water and emergency rations. About 30,000 of the town's 40,000 residents reportedly perished in the disaster.

Misawa also said there were problems with transporting supplies.

"The only airport in Meulaboh is out of use and helicopters are the only means of transportation," he said. Peace Winds borrowed a helicopter from the Indonesian army and shared a chartered Cessna with media companies to deliver its supplies.

The Foreign Ministry said at least 18 nongovernmental groups were in the region as of Tuesday, including eight groups under Japan Platform, a government-business initiative for helping relief efforts carried out by nongovernmental organizations.

On Dec. 28, the government decided to allocate 23 million yen to Japan Platform, which comprises 16 separate Japanese relief groups, including Peace Winds.

BHN Association, Japan, a Tokyo-based nonprofit organization providing telecommunications support that is also a member of Japan Platform, said Sri Lanka's telephone network has been severely damaged, leaving thousands unable to contact relatives or get basic information.

Since most of the phone network's base stations were set up on the coast, many were swept away, the group said. In the southeastern city of Hambantota, almost all of the stations were lost. Even areas where stations were spared are isolated because many families lost their home terminals to the tsunamis, it said.

BHN is providing mobile and satellite phones to the victims and is considering setting up an FM radio station in Hambantota.

A separate group, the Association of Medical Doctors of Asia, has sent more than 80 doctors, nurses and other medical staff to Indonesia, Sri Lanka and India. The group said its greatest fear is an epidemic. The group, which is not a member of Japan Platform, is focusing on preventive measures, including spraying disinfectant and issuing warnings.