A Peruvian Boeing 737-200 went down in a storm near the Amazon jungle city of Pucallpa, killing 70 of the 100 people on board, Peruvian President Alejandro Toledo announced.
Only about 20 or 30 of the 93 passengers and seven crew members survived the crash on Tuesday of the Tans Airlines flight from Lima, Toledo said.
Transportation Minister Jose Ortiz had previously said most of those aboard had survived.
The aircraft was 4.8 km from Pucallpa airport when it crashed near a road, according to a control tower official. The official said a storm had broken out as the plane approached the airport.
A Peruvian radio reporter at the scene said he saw several dead bodies, and a survivor said he had seen more than 20 people injured, mostly with burns and fractures.
The reporter said he saw dead children, including babies, around the crash site. He also saw the body of a woman in a flight attendant's uniform.
One of the survivors, Tomas Ruiz, told the reporter that the plane appeared to be affected by the bad weather.
"With 10 minutes remaining for us to land in Pucallpa, we noticed that the plane was moving too much because of the weather," he said.
Another survivor, William Zea, nursing a burned hand, said, "The plane had problems and we fell."
According to the Aviation Safety Network, the crash was the sixth for Tans since 1992.
The crash -- the fifth in August month involving a passenger plane -- comes a week after a chartered Colombian jetliner crashed in Venezuela, killing all 160 on board.