At least 36 people killed after Soviet-era plane crashes near capital’s international airport shortly after takeoff.

Juba, South Sudan – A cargo plane has crashed shortly after takeoff in Juba, South Sudan, killing dozens of people and raising questions about security at the country’s main international airport.

On Wednesday morning, the Soviet-era Antonov-12 pummeled into a grove of fruit trees on the sparsely populated east side of the Nile river, according to witnesses at the scene of the crash.

It was unclear exactly how many people were on board.

Minister of Transportation Kuong Danhier Gatluak told Al Jazeera that 36 people were killed, and more may be unaccounted for. Authorities are still investigating the cause.

Al Jazeera counted 25 bodies, including several children.

Presidential spokesman Ateny Wek Ateny told Al Jazeera the plane was heading for the Paloich oil fields in the country’s north.

Ateny said there were 18 people on board the aircraft when it crashed, including 12 South Sudanese, and six members of an Armenian and Russian crew.

He said three South Sudanese survived, including an infant, and 10 more people were killed on the ground.

Ateny said the company was illegally carrying passengers on a cargo flight.

“It is the problem for the company now to address,” he said.

The spokesman said a local businessman chartered the flight, but had no more information.

Bodies were found on the muddy riverside along with the craft’s cargo, rubber flip flops, medicine, tires, and cans of beer and energy drinks.

Barefoot responders gathered the sandals and wore them to be able to access the uninhabited, swampy crash site.

The front of the fuselage was destroyed and the wings were torn off, with propellers mangled in the mud.

Only the tail, marked with the logo of Allied Services Limited, a Tajikstan charter company operating in South Sudan, was intact.

Witnesses who live near the crash site said no one was on the ground where the plane hit, contradicting the presidential spokesman.

“Nowehere to run”

Ismail Ibrahim Mohamed, a farmer whose house is closest to the crash site, told Al Jazeera he heard a loud noise and came running to the scene after the crash.

“We saw the plane as if it was landing, and there was nowhere to run,” he said.

Mohamed said a tree stopped a tire from hitting his children who were sleeping.

Kenyi Galla, an operations manager for charter company Combined Air Services, which had a staff member on board, said the plane was overloaded.

Security officials at Juba International Airport force cargo crews to take passengers on board, he said.

“I see it every day. I work in the airport,” he told Al Jazeera while searching for his colleague’s body. “They use military force to put their wives and kids on.”

Al Jazeera’s Hiba Morgan, reporting from Juba, said bad weather was hampering the rescue effort.

“It is raining hard here in Juba, making it difficult to look for more victims,” she said. “The cargo plane was carrying passengers and it is believed that many of them were not wearing seat belts.” Map of Juba in South Sudan map [Al Jazeera]

Juba’s airport is the busiest in the war-torn country.

The airport hosts regular commercial flights, as well as military aircraft and cargo planes delivering aid to remote regions cut off by road.

Civil war broke out in December 2013, when President Salva Kiir accused his former deputy, Riek Machar, of planning a coup, setting off a cycle of retaliatory killings that has split the landlocked country along ethnic lines.

Fighting continues despite an August peace deal, but battles today are far from the capital.