JUBA: An official says at least 18 people were killed Wednesday when a small plane crashed in a remote part of South Sudan.

The flight, chartered by Chinese oil firm Greater Pioneer Operating Company, had 21 people on board, including two pilots, said Gatwech Bipal, the minister of information in the oil-rich Unity state, where the crash happened earlier on Wednesday.

The plane crashed while it was taking off near an oil field to head to the international airport in Juba, the South Sudanese capital, he said.

It was not immediately clear what caused the crash, and authorities had not yet revealed the identities of the victims. Local media reported that the plane was carrying oil workers.