Rio De Janeiro, Brazil ? A Brazilian jetliner with 155 people aboard was reported missing Friday over the Amazon jungle, aviation authorities said.

Initially, officials said they thought Gol airlines flight 1907 had collided with a smaller plane after leaving the jungle city of Manaus in the remote southwestern region of Para state. News reports said the plane struck a Brazilian-made Legacy, a smaller executive jet.

But authorities later said they were no longer certain the disappearance was caused by a collision with a private jet.

“During the afternoon, there was another incident with a Legacy airplane, made by Embraer,” federal aviation authorities said in a statement issued early this morning. “It is impossible to confirm that there is a relation between the incident which caused the (Legacy) crew to perform an emergency landing in Cachimbo and the disappearance of the Gol airplane.”

Initially, authorities reported the collision was near the Serra do Cachimbo region in Para state, but the Legacy managed to land at the Cachimbo base despite suffering damage. The aviation agency said the plane disappeared about 130 miles south of the city of Cachimbo, some 1,250 miles northwest of Rio de Janeiro.

The jetliner had been scheduled to make a stop in Brasilia before heading to Rio’s Antonio Tom Jobim International Airport. Manaus is a major river city in the heart of the Amazon rainforest, some 1,700 miles northwest of Rio.

Brazilian airport authority President Jose Carlos Pereira said five air force planes were searching for the missing Boeing 737 in a densely forested region and would continue to search through the night.

On Friday evening, Gol issued a brief statement confirming the plane’s disappearance.

“GOL informs that flight 1907, that today left the Manaus airport at 15:35 (Brasilia time) this Friday, and was scheduled to arrive at the Brasilia airport at 18:12, has not had its landing confirmed until this moment. We are awaiting information from officials of the aviation authorities about the flight,” the statement said.

Gol said there were 155 people aboard: 149 passengers and six crew members.

Pereira said in an interview with CBN radio that a local farmer reported seeing a large plane flying low.