The Ugandan army said Tuesday that nearly 1,000 former M23 rebels had escaped from a camp just before their scheduled repatriation to the Democratic Republic of Congo.
The army's chief spokesman, Lieutenant Colonel Paddy Ankunda, said the fighters cited security fears as their reason for not returning to the DRC.
Ankunda, communicating via Twitter, said the Ugandan government was looking for the escaped fighters.
Earlier in the day, Bertrand Bisimwa, civilian head of M23, said the fighters had fled as trucks arrived at the Bihanga military camp to take them to an airbase, where they would be airlifted to the DRC. He said some of the fighters had been shot and wounded during their escape.
A number of M23 fighters ended up in Uganda last year after the Congolese army drove the rebels from their strongholds in Congo's North Kivu province.
The DRC has promised amnesty to fighters who agree not to take part in future insurrections. But Bisimwa said the M23 fighters would face prosecution or be killed if they returned to Congo because they have no protection there.
Ankunda said 120 M23 fighters had expressed willingness willing to return and were taken to Entebbe airport Tuesday for repatriation.
M23 consisted of fighters who joined the Congolese army in a 2009 peace deal but later defected after complaining of poor treatment.
Congo has accused neighboring Rwanda and Uganda of supporting M23, an allegation both countries deny.
Some information for this report comes from AP, AFP and Reuters.