JUBA (Reuters) - South Sudanese rebels are holding two Kenyan pilots and will not release them until compensation is paid to the family of a civilian killed when their plane crashed, a rebel spokesman told Reuters on Tuesday.

The plane crashed in Akobo, in the Greater Upper Nile region, two weeks ago, Lam Paul Gabriel, the rebels’ deputy spokesman, said.

“When the plane crashed, it took a life. There was a lady that was killed and also there were some animals killed. The relatives of the lady and the owners of the cows are complaining they want compensation,” he said.

“They (Kenyan leaders) have to write an official letter to Dr. Riek Machar and it will come to us to inform of an order, then we will release him.”

Machar, the country’s former vice president, is the head of the largest rebel faction but has been held under house arrest in South Africa since 2016.

South Sudan’s military spokesman confirmed the two pilots were being held.

“The plane had a technical problem. It crash-landed and killed a person on the ground,” said Brigadier General Lul Ruai Koang.

“The (rebel) SPLA-IO-appointed governor of the area has demanded the ransom of $200,000 which is beyond normal compensation for any person killed,” he added.

The Kenyan foreign ministry said it was unable to comment.

Oil-rich South Sudan has been riven by civil war since 2013. The conflict has displaced a third of the population, shut down most of the oil production and wrecked the economy.