Updated

Congolese authorities were investigating Saturday how many people died after the cargo doors on a Russian plane opened at 33,000 feet and dozens of men, women and children were sucked out.

The flight crew managed to fly the plane back to the capital.

Confusion over the death toll persisted.

Two officials at the international airport told The Associated Press that 129 people were feared dead. Later, a third official estimated the casualties were about half that, saying the exact figure may be difficult to determine because of an incomplete passenger list. The officials spoke on condition of anonymity.

The defense ministry of Ukraine, which owns the plane, denied anyone was hurt and said no cargo was lost.

Seven people were confirmed dead and military helicopters searched the region for bodies, said government spokesman Kikaya Bin Karubi. He did not provide details but confirmed that those who died were "ejected from the plane."

The cargo doors of the plane, a Russian-built Ilyushin 76, opened about 45 minutes after takeoff Thursday night from Kinshasa.

"The door opened and the plane depressurized. Many were sucked out," said Kabamba Mbwebwe, a doctor who treated victims.

Nine survivors were treated for minor injuries and psychological trauma at Kinshasa General Hospital.

One passenger, police Lt. Ilunga Mambaza, estimated that 350 passengers were on the plane when it took off but only 100 returned, meaning about 250 people died.

"Lots of my colleagues were sucked out by the wind. I don't know how many, because I fainted," Mambaza said.

Survivors said passengers clutched military vehicles and ladders trying to remain inside the plane after the doors opened. People in Africa often travel on modified cargo planes that have few seats, leaving most passengers to cram in among their belongings in the rear of the aircraft.

Police Sgt. Kabmba Kashala, who also was on board, said the aircraft took off with the door improperly fastened. Three attempts to shut it correctly during the flight failed and then it sprang open, he said.

"I was just next to the door and I had the chance to grab onto a ladder just before the ... door let loose," he said.

He put the number of missing at about 100.

Disputing the witness accounts, Ukrainian Defense Ministry spokesman Kostiantyn Khyvrenko said that about 40 seconds after takeoff from Kinshasa, the aircraft captain noted that the cabin was depressurizing, requested a landing and successfully returned the aircraft to the airport. He cited officials of the state-owned company that operates the aircraft, Ukrainian Cargo Airways.

"Neither the people, nor the cargo, nor the plane itself were hurt or damaged," Khyvrenko told The Associated Press in Kiev, Ukraine.

The plane apparently had been chartered to transport Congolese soldiers and their families from Kinshasa to the southeastern city of Lubumbashi, a diamond center. Soldiers regularly provide security in Congo cities, often traveling as a group between assignments.

The weather was clear and there were no suggestions of sabotage.

The Ilyushin 76 is a medium- to long-range transport jet. The model was first flown in 1971. It is widely used as a civilian carrier, particularly in Africa, the Middle East and Asia.

The plane has a checkered safety record, including 47 accidents that resulted in 668 deaths, according to the Aviation Safety Network Web site, an air safety data base.

On Feb. 19, an Ilyushin 76 crashed in bad weather in Iran, killing 275 people, including more that 200 elite Iranian soldiers. A month earlier, another jet crashed while landing in thick fog in East Timor, killing all six people on board.

As many as 1,000 people were killed in Kinshasa on Jan. 6, 1996, when a Russian-built Antonov crashed into a crowded market at the end of a runway near a Kinshasa airport.

Congo is in the fifth year of a civil war that has led to more than 2.5 million deaths, aid groups estimate, mostly from strife-related hunger or illness. Despite a series of peace deals, fighting persists in the northeast.