"The rebels are present at Kalma (camp) now because they attacked our police four times," said al-Hajj Attar al-Manan, the governor of South Darfur state, on Wednesday.
Al-Manan said authorities in South Darfur had taken steps to halt attacks by the Janjawid.
"We arrested so many members of the Janjawid - more than 70 persons from the Janjawid are now at the prison of Nyala and will be committed to the court," he said.
He called on the international community to help disarm all the Darfur tribes, saying guns were easy to obtain because of previous conflicts in neighbouring countries.
Rebels fought with government
forces on 9 December
Al-Manan said there was suspicious activity in the Otash and Direij camps but said he could not confirm a rebel presence there.
Some government aid officials have in the past accused rebels of smuggling weapons into refugee camps.
The governor said those camps on the outskirts of Nyala were scheduled to be relocated to better facilities away from Nyala, while the Kalma camp was due to be relocated because it was on private land and near the Nyala airport.
Past relocation efforts by the government have met with resistance from camp residents who say they fear for their lives if they are moved.
Al-Manan also denied reports government planes had bombarded Marla from the air last week.
"Our evidence is that the rebels burned this village"
Al-Hajj Attar al-Manan,
Governor, South Darfur
"No there is no utilising of Antonov planes," he said. "Our evidence is that the rebels burned this village."
Aid agencies working in Marla town were evacuated after fighting broke out between government forces and rebels on 9 December.
More than 1.6 million people have fled their homes in Darfur since the start of the conflict. The United Nations calls the situation in Darfur one of the world's worst humanitarian crises.