JUBA, Sudan(AFP) — Hollywood star George Clooney is on a tour of south Sudan drawing attention to his fears for war as the region builds up to a vote on whether to break away from Africa's biggest nation.

Clooney is accompanied by a US television channel which has been giving details of his visits to mass graves and conversations with tribal elders.

"If you knew a tsunami was coming ... what would you do do to save people?" Clooney was quoted as saying by NBC journalist Ann Curry when he was asked about the likelihood of conflict in south Sudan, which is scheduled to have a referendum on January 9 on whether to remain part of Sudan.

She said in an earlier statement on her Twitter account that Clooney "fears a war is coming here."

Curry said the Hollywood star had visited a mass grave and had spoken to local tribal leaders. He is due to give an account of his visit next week in Washington.