World Wide Fund for Nature's (WWF) Director General James P. Leape said on Sunday (September 24) he is hopeful that a missing helicopter in Nepal and its passengers will be found safe. Heavy rain and thick clouds hampered the search on Sunday for a helicopter chartered by the conservation group which disappeared in bad weather with 24 people on board. Radio contact with the Russian-built MI-17 helicopter was lost on Saturday (September 23) in Taplejung district, a remote mountainous area 300 km (190 miles) east of the capital, Kathmandu. Army and civilian helicopters and ground rescue teams began combing the forested hills for the aircraft which was carrying 17 Nepali nationals and seven foreigners. "The search has been somewhat impeded by bad weather, it's been rainy up there, but it is now under full swing and we hope they will find the helicopter soon", Leape told Reuters. "We don't know what happened to the helicopter, all we know is that it didn't arrive where it was supposed to arrive, so our hopes of course are that they will find the helicopter and the people safe", he said. Among the flight's 20 passengers and four crew were Nepal's Forest Minister Gopal Rai and his wife, Finnish Charge d'Affaires Pauli Mustonnen, and deputy director of the U.S. Agency for International Development in Nepal, Margaret Alexander. In their website, the WWF said seven of its staff were also on the helicopter, three from WWF-Nepal, two from WWF-UK and two from WWF-US. Four WWF staff were Nepali -- Nepal Country Representative Dr Chandra Gurung, Biodiversity expert Mingma Norbu Sherpa, local advisor Dr Harka Gurung and Senior Programme Officer Yeshi Lama. The others were the Swiss-Australian Conservation Director of WWF-UK, Dr Jillian Bowling Shlaepfer, Canadian Jennifer Headley, who was Eastern Himalayas Regional Coordinator, and American biodiversity programme officer Matthew Preece. Two of the helicopter's crew were Russians. Nepal's tourism minister Pradip Gyanwali said the government would give $2,700 as reward to anyone providing information about the missing aircraft. The helicopter left Ghunsa village at about noon (0615 GMT) but never arrived at its destination in Taplejung town, a 20-minute flight. The passengers had attended the handover of a WWF project to the local community and were on the way back. It was raining heavily in the area where the aircraft disappeared, airport officials involved in the rescue operation said. There are more than a dozen private airlines in Nepal, which has poor roads and some of the world's highest peaks. Eighteen people, including 13 Germans, were killed when a private airliner crashed in the hills of western Nepal in 2002.