Searchers on Monday found the wreckage of a helicopter that disappeared over the weekend while carrying 24 people on a flight chartered by the World Wildlife Fund. No one survived, officials said.

Among those killed in the crash in the mountains 250 miles east of Katmandu were Americans Margaret Alexander, a USAID deputy director in Nepal, and Matthew Preece, a WWF program officer, according to a statement on the conservation group's Web site.

CountryWatch: Nepal

The helicopter was also carrying Nepalese Forestry Minister Gopal Rai, Finnish Embassy Charge d'Affaires Pauli Mustonen and Canadian Jennifer Headley, a coordinator for WWF.

Several Nepali journalists, government officials and four crew members — two Russians and two Nepalis — were also on board.

The World Wildlife Fund offered condolences and support to the families of the victims, saying the deaths amounted to the biggest single loss of life in the organization's 45-year history.

"The colleagues we have lost had dedicated their lives to conserving the extraordinary natural resources of Nepal and of the earth. Their deaths are a huge blow to conservation efforts in Nepal, and worldwide. They will be greatly missed," WWF Director General James Leape said in a statement.

Purushottam Shakya, of Nepal's Civil Aviation Authority, said a seven-man search team that reached the wreckage on foot reported there were no survivors. The helicopter had been missing since Saturday.

Shakya said rain and low visibility caused the effort to recover bodies to be suspended Monday night. The operation was to resume early Tuesday.

Also hampering the recovery was the inability of helicopters to land near the wreckage, Nepali officials said. The closest landing spot was a two-hour trek from the crash site.

The helicopter left Ghunsa village, where the passengers visited a WWF project, on Saturday morning, but failed to arrive as planned at Suketar village, a 20-minute flight away. Both villages are in the Taplejung district.

The WWF statement said the helicopter appeared to have hit a rock outcropping on a ridge, causing it to smash down into a nearby clearing.

The search for the helicopter had been hampered by rain and fog in the mountainous area. Mountain guides, soldiers, police and villagers combed the area on foot looking for the aircraft.

The Russian-built Mi-17 helicopter was chartered from Shree Helicopter Co., the Civil Aviation Authority of Nepal said.

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