Air force search planes found on Saturday the wreckage of a Brazilian passenger plane that crashed a day earlier in Amazon jungle with 155 people on board and there were no reports of survivors.
The brand-new Boeing 737-800 operated by Brazilian low-cost carrier Gol probably plunged into the ground nose first, Brazil's airport authority said on Saturday.
Search planes found the crash site in Mato Grosso state, about 1,000 km northwest of the capital Brasilia in a dense forest area that was difficult to reach, officials said.
The plane disappeared on Friday afternoon after what could have been a mid-air collision with a smaller plane, local officials and media reports said.
Authorities lost radar contact with Gol flight 1907 during its flight from the principal Amazon city of Manaus to Brasilia, the airline said.
Gol and civil aviation officials could not confirm if there were any survivors among the 149 passengers and six crewmembers on board.
The president of the airport authority Infraero, Jose Carlos Pereira, said the pattern of the wreckage indicated that plan had smashed into the ground nose first.
"Imagine the velocity at which it hit the ground coming from an altitude of 36,000 feet (11,000 meters)," he told reporters.
Denise Abreu, director of civil aviation authority ANAC, said signs indicated there had been a mid-air collision with a smaller jet, which landed safely.
Embraer aircraft manufacturer said one of its executive jets, a Legacy 600 owned and operated by a client, had been involved in a collision.
The jet made an emergency landing at Cachimbo air force base with five passengers on board, Embraer said. No injuries were reported.
The mayor of a town in Mato Grosso said the plane had crashed on Jarina farm in Peixoto de Azevedo municipality, but the farm's manager later said that employees of a nearby farm only saw a big plane on Friday evening flying low and then lost it from sight.
"People saw a large plane making strange manoeuvring and losing altitude," Ademir Ribeiro said by telephone.
"The native forest is thick here, so they lost visual contact because of the trees," he said, adding that it was impossible to say if that was a Gol plane.
The plane had been received new from Boeing on September 12 and had only 200 flight hours, the company said.
Manaus is host to a number of foreign-owned manufacturing plants making motorcycles, computers and other goods in its duty free zone. It is also a base for tourism in the Amazon, the world's largest rain forest, and a headquarters for several environmental groups.
At Brasilia airport, dozens of friends and relatives, many weeping, gathered anxiously to await news.
Gol is a low-cost carrier that has expanded rapidly since its founding in 2001 to become Brazil's No 2 airline and to offer flights to neighbouring countries.
With its orange and white colours and stylised casual uniforms based on US no-frills carriers, it is an instantly recognisable brand in Brazil and one of its most successful new businesses.
In the last major airline crash in Brazil, 33 people were killed when a plane belonging to regional carrier Rico Linhas Aereas crashed in the Amazon flying from Sao Paulo de Olivenca to Manaus on May 14, 2004.