Four passengers and three crew were killed Saturday when a cargo plane belonging to a local operator crashed near South Sudan's capital Juba, the transport minister said.

The aircraft crashed shortly after its early morning takeoff in the Kameru neighbourhood around seven kilometres west of the city's international airport.

"There were eight people on board, three passengers and five crew. A single person from among the passengers survived and she is in good health," Transport Minister Madut Biar Yol told AFP.

"The four other passengers and the three crew members are dead."

According to the minister, the crew members were Russian while the passengers were all South Sudanese.

The plane owned by local company South West Aviation had been carrying cash to the Wau region in the country's northwest for Juba-based Opportunity Bank.