A Kenya Airways passenger plane with 114 people on board crashed in a densely forested area of southern Cameroon on Saturday shortly after takeoff, government and aviation officials said.
Military and civil aviation helicopters were scouring a wide zone in the central African country between Kribi on the Atlantic coast and Ngomedzap, south of the capital Yaounde.
"The search is underway but the accident site has not yet been found," the Transport Ministry said in a statement. State radio earlier reported the plane crashed near Nieté, north of the border with Equatorial Guinea, after taking off from Cameroon's second city of Douala.
"We were not able to locate any wreckage at Nieté where first information suggested the crash may have occurred," a local government official in southern Cameroon told Reuters.
He said the search had shifted to another area south west of the capital - between the towns of Lolodorf and Ebolowa - where inhabitants said they had heard a loud explosion. In Nairobi, Kenya Airways Group Managing Director Titus Naikuni said authorities in Cameroon had picked up an automatic distress signal from the area where the plane went missing.
"The distress call came from a machine, not a pilot," he said. Kenya Airways said the 737-800 airliner, which began its journey in Ivory Coast's main city Abidjan and stopped over in Cameroon, was carrying 105 passengers and nine crew.
The airline said there were Cameroonians, Indians, South Africans, Chinese, Nigerians, Ivorians, Britons and an American among the passengers. The nine crew were all Kenyans.
The company said the Douala control tower had received the last message from the aircraft right after takeoff. The plane had been due to land in Nairobi at 6:15 am (0315 GMT). Kenyan Transport Minister Chirau Ali Mwakwere said the US government was assisting in the search with satellite images taken over the expected flight path.
A handful of worried relatives came to seek information at Nairobi's Jomo Kenyatta International Airport. One woman passed through the lobby wailing, mobbed by journalists before she was ushered away by security staff. Kenya Airways, one of Africa's few profitable carriers, set up a crisis centre to monitor events and a passenger information centre at a hotel in Nairobi.
The carrier generally has a good safety record on a continent where air accidents are above the world average. The plane was six months old and had no history of problems, Naikuni said. Kenyan media reported there was rain in Douala when the plane took off. On January 30, 2000, a Kenya Airways Airbus A-310 crashed into the sea shortly after takeoff from Abidjan, killing 169 of the 179 passengers and crew.