Unknown gunmen killed a radio journalist in South Sudan’s Warrap State on Wednesday. 

Marko Agei Makhor was shot and killed on his way to Tonj town from his home village, David Jong, the station manager of Door Radio 99.9 FM, told Radio Tamazuj on Thursday.

Jong said Marko Agei had been working as a journalist for Door Radio 99.9 FM in Tonj town for a long period of time. “What happened is that Marko went to Manyangok village and while on his way back to Tonj he was shot dead. We don’t know who killed him,” he said.

The station manager said the motive behind the killing of the radio journalist remains unclear.

There was no immediate claim of responsibility for the killing in the area.

Police authorities in Tonj have promised a "full" investigation into the killing of journalist Marko Agei.

Col. Mayiey Aru, head of the Criminal Investigation Department (CID), said they will leave no stone unturned as part of the investigation into the killing of journalist Marko.

According to Reporters Without Borders, at least 10 journalists have been killed in the country since 2011. 

South Sudan is ranked 138th out of 180 countries on the World Press Freedom Index this year.