A rebel group in Sudan's Darfur region has freed 49 international peacekeepers it had captured earlier, according to its spokesman.
The Justice and Equality Movement (JEM), Darfur's largest armed opposition group, told the Reuters news agency earlier on Monday that they had captured 52 members of the UNAMID force.
"All peacekeepers are free but we are holding three Sudanese accompanying them," JEM's spokesman said.
A spokeswoman for UNAMID said the peacekeepers had been allowed to leave but were staying in the area in north-western Darfur since they did not want to leave the three detained civilians behind.
Gibril Adam Bilal, a JEM spokesman, had said his group was holding the peacekeepers to determine why they entered rebel territory, "and to investigate the three Sudanese because we think they are members of Sudan's intelligence and security service".
Sources tell Al Jazeera, however, that the detained officials are UN civilian personnel.
Forty-six of the peacekeepers were from Senegal, including two officers, while there was one each from Yemen, Ghana and Rwanda, sources said.
Senegalese troops operate primarily in Darfur's northwest near the Chad border.
JEM announced in January that it had chosen Gibril Ibrahim, a one-time university professor, to head the movement after his brother Khalil, its former leader, was killed.
The new chief denied JEM had fractured and said the group would follow the course set by his brother to seek "democratic" change.
Earlier this month JEM released five Turkish citizens who, the group said, had been hired to dig wells for the Sudanese military. They were held for several months.
The UN estimates that at least 300,000 people have died as a result of the Darfur conflict, since rebels took up arms in 2003. Almost two million people remain displaced.
The Sudanese government puts the death toll figure at about 10,000, and says the number of casualties has been exaggerated for political reasons.
Last year the government signed a peace deal in Qatar's capital, Doha, with an alliance of Darfur rebel factions. JEM and other key rebel groups refused to sign the pact, saying it failed to address the Darfur problem at its roots.
Omar al-Bashir, Sudan's president, is wanted by the Hague-based International Criminal Court for alleged genocide, crimes against humanity and war crimes in Darfur.