abuja, nigeria - Nigerian authorities say a rehabilitation program for former Boko Haram sect fighters is helping weaken the group's fighting power. Nearly 600 fighters graduated from the program over the weekend and tendered a public apology for their actions. Authorities say they will be reintegrated into society, but experts are warning of possible relapse.

The former Boko Haram fighters dressed in white simultaneously and echoed an oath of allegiance to Nigeria during a graduation ceremony Saturday at the De-radicalization, Rehabilitation and Reintegration (DRR) camp in northern Gombe state.

They're the latest batch of voluntary defectors from the sect to undergo the six-month physical, mental and psychosocial rehabilitation program tagged Operation Safe Corridor.

Nigerian authorities started the safe exit program in July 2016 as a strategy to degrade the fighting power of terror groups like Boko Haram.

Program coordinator Uche Nnabuihe spoke via a military broadcast during the ceremony.

'Based on the therapeutic interventions these sets of clients have undergone, they're better citizens from when they initially arrived at the DRR camp and accordingly are certified fit for graduation and subsequent reintegration to their respective communities," Nnabuihe said.

Authorities said three of the graduates are from Niger and one from Chad, while the rest are Nigerians mostly from Borneo, Adamawa, Yobe, Zamfara, Niger and Nassarawa states.

The former fighters offered a public apology and promised to embrace peace in their respective communities.

Security analyst Senator Iroegbu said in theory the program could help but warns there could be relapses.

'Repentance is a thing of the mind," Iroegbu said. "Someone can pretend to have repented because the conditions to express himself otherwise are not there. This is a controversial program in many facets. There'll always be resistance to it. What has been the impact? Has it been able to stop more recruitment?'

Authorities say thousands of repentant Boko Haram members have been freed since 2019 and that they have become productive members of society.

But in 2021, Borno State Governor Babagana Zulum called for a review of the program, saying ex-Boko Haram members spy on communities and then rejoin the group.

Local communities in Borno, which is the epicenter of the Boko Haram insurgency, have also questioned the program.

Vivian Bellonwu, founder of Social Action Nigeria, explained why.

'It appears rehabilitation attention has mostly been focused on the rebels themselves, whereas the communities also suffered very far-reaching trauma," Bellonwu said. "And they are actually supposed to undergo psychological, psychosocial rehabilitation. And I have not seen this sufficiently being done for them.'

Bellonwu said it will not be easy for the former fighters to be accepted back into the communities they once harmed.

'These are communities that have been abducted en masse, Bellonwu said. "Their women have been raped. Some of the children have watched their parents being slaughtered by these elements. These kinds of things have a way of having a lasting impact in the minds of the victims. How do you expect them to forget?'

Boko Haram has been fighting to create an Islamic caliphate in northern Nigeria since 2009. The violence has led to tens of thousands of deaths and spilled over into neighboring Niger, Chad and Cameroon.

On Sunday, Nigerian defense authorities said some 51,000 Boko Haram militants and their families surrendered to Nigerian forces between July 2021 and May 2022.