Kathmandu, Nepal — Eight days after Nepal’s earthquake, three survivors were found beneath the rubble of destroyed buildings, officials said Sunday.

An Icelandic Red Cross official said the survivors were found about 12 miles from Chautara in Sindhupalchok district in northeast Nepal, about 40 miles northeast of the capital Kathmandu.

The survivors reportedly were flown to Kathmandu for medical treatment.

Some Nepalese officials had dismissed chances of finding more survivors after two were found on Thursday in Kathmandu. But U.S., Nepalese, Chinese and other search-and-rescue teams continue to comb through rubble for survivors.

Foreign assistance to the stricken nation has largely been funneled through Tribhuvan International Airport. Though passenger service was closer to normal Sunday, the facility is still subsumed by the disaster, a week after the quake turned it into a hub of despair and frustration.

Outside the Tribhuvan airport terminal, people looking for missing travelers from Asia and Europe posted signs, some with pictures of backpackers who disappeared in avalanches triggered by the magnitude 7.8 quake on April 25.

More than 6,600 people died in the quake, and Nepalese officials have said they expect that number to increase as they reach remote areas and comb the rubble.

The first flights carrying about 500 U.S. forces, heavy equipment and helicopters were expected to arrive Sunday afternoon, officials said.

U.S. Marine Brig. Gen. Paul Kennedy, who is commanding the operation, arrived at the airport Sunday with a half a dozen other uniformed U.S. service members.

“We’re just here making sure nothing goes off the rails,” Kennedy said. “You see that tarmac. It’s busy. You’ve got flights coming in from Thailand and if you’re late, you lose your slot. So that’s why we’re here.”

The United Nations has asked the Nepalese government to relax customs controls it says have delayed relief shipments. Nepalese army officials at the airport said they have already improved screening of plane manifests at customs and have suspended fees, but that minimum screening is still necessary—especially to prevent fraud.

The U.S. operation is designed to streamline the delivery of aid at the airport and in more rural areas.

Among the first U.S. aircraft to arrive will be four vertical-takeoff Osprey that will be joined by Army Chinook helicopters capable of ferrying cargo to mountain communities devastated by the quake whose roads were blocked by landslides.

U.S. forces will also bring forklifts to more quickly unload and route shipments.

The flights will take off and land from Tribhuvan airport and several smaller airstrips and helicopter landing zones around the country, Kennedy said. U.S. aircraft are not expected to deliver goods directly to towns or villages but instead will ferry them to distribution points where Nepalese authorities and international aid agencies will take charge.