Nineteen people were killed when a small passenger plane crashed into a lake as it tried to land in thick fog in central South Sudan, reports say.

Only four people, including two children, survived the crash, said government official Taban Abel Aguek.

The victims include the pilot and co-pilot, a staff member of the Red Cross and an Anglican bishop, he told AFP.

The aircraft was carrying 23 people from the capital, Juba, to the city of Yirol on Sunday.

"When it arrived the weather was so foggy and when it tried to land it crashed into Lake Yirol adjacent to Yirol town," Mr Abel Aguek, the regional government minister, said.

"The whole town is in shock, the shops are closed, some people have taken their relatives for burial. It is a commercial plane that crashed," he added.

Images posted on Twitter by Radio Miraya showed the twisted wreckage of the aircraft submerged in water as local fishermen used canoes to help with rescue and retrieval efforts.

In March last year, a plane travelling from Juba to Wau, in the north-west of the country, crashed with at least 40 people on board. None of the passengers were killed but several were taken to hospital with serious injuries.