Adjust font size:
KATHMANDU, Nepal (CNN) -- Weather conditions hindered Sunday the search for a helicopter carrying 24 people that crashed in a remote area of Nepal, authorities said.
Nepal's Civil Aviation Ministry said Sunday three helicopters searched for the missing craft, but the operation was called off due to inclement weather and poor visibility.
Airport officials are planning for a third search mission, but are waiting for conditions to improve.
The crash was reported by an army helicopter pilot flying in Nepal's eastern district of Taplejung, Hemant Kumar Uprety, a Taplejung airport worker, said.
Local villagers also reported hearing two loud explosions shortly after the helicopter's take-off, he added.
The first one occurred five minutes after the helicopter took off and the second one occurred 15 minutes later, he said. Officials have speculated the second blast was from the helicopter's gas tank exploding.
The Shree Air helicopter went missing Saturday while traveling from the Kanchenjunga Nature Conservation Reserve to Suketar in Taplejung.
The passengers, who were to catch a flight to Kathmandu, included several high-ranking officials from United States Agency for International Development (USAID) and the World Wildlife Fund (WWF).
An official from the Finnish Embassy in Kathmandu, and Nepal's State Minister for Forests and Soil Conservation, Gopal Rai, were also aboard.
A WWF spokesman in Nepal, Basant Subba, said there were 20 passengers and four crew members on the helicopter.
The passengers were there to manage the Nepalese government's handover of the conservation of wildlife in Kanchenjunga to a coalition of local communities, Subba said.
Kanchenjunga is the third-highest mountain in the world, and is on the Nepalese and Indian border.
Jeffrey Grieco, a USAID spokesman, told CNN that the U.S. government was notified a couple of days ago Nepalese time about a helicopter that did not check in, and that the government was still waiting to hear their fate.
"Our thoughts and prayers are with their families and our hope is that they will be found unharmed," Grieco said.
Taplejung is about 500 kilometers (310 miles) east of Kathmandu, the capital of Nepal.
From CNN's Suman Pradhan and Elise Labott.