Darfur - Rebels in Sudan's Darfur region said on Monday they had freed all 49 international peacekeepers captured one day earlier but that they continued to hold three Sudanese.

"We released the peacekeepers because our investigation confirmed that they came to our area without knowing it is under our control," Gibril Adam Bilal, spokesman for the rebel Justice and Equality Movement (JEM), told AFP.

He said the movement still held the three Sudanese -- initially suspected to be government security agents -- while it verified what they were doing with the peacekeepers.

"If the investigation confirms that they are not security members we will release them immediately," he said.

A UNAMID public information officer said the three civilians work for the peacekeeping mission, not the government.

"They are not spies," she said, declining to say what had happened to them.

She gave the number of peacekeepers as 55 and said they are able to move but are "working on releasing" the civilians who were with them.

The troops had not been taken hostage, she said.

Bilal said earlier the UN troops had been captured while the rebels probed why they had entered a JEM-controlled area without permission and without informing the insurgents.

He said the peacekeepers and their equipment were safe. Forty-six of them were from Senegal, including two officers, while there was one each from Yemen, Ghana and Rwanda.