All 64 suspected Boko Haram commanders and men were among the 416 inmates that escaped from the Kuje Correctional Centre in Abuja following the Tuesday night attack.
Four inmates and an operative of the Nigerian Security and Civil Defence Corps (NSCDC) were killed.
The Islamic State of West Africa Province (ISWAP) last night claimed responsibility.
Permanent Secretary in the Ministry of Interior Dr. Shuaib Belgore spoke on how the terrorists invaded the facility.
According to him, the assailants came determined as they fought security operatives for over 30 minutes.
He said reinforcement was called but the terrorists escaped before support arrived.
Minister of Defence, Maj.- Gen. Bashir Magashi, added that the attack pattern pointed to Boko Haram insurgents.
According to him, the insurgents came in large numbers and attacked the facility at about 10.25pm.
He said all security personnel within the facility responded in equal measure to the attackers.
He said: “From the records, they belong to a particular group – the Boko Haram insurgent group. And all of them inside the facility have escaped.”
Inspector-General (IG) Usman Alkali ordered the deployment of the Explosives Ordnance Disposal (EOD) Unit, forensic experts and other special forces to the Centre.
Police Spokesman, Muyiwa Adejobi, said all relevant security agencies were working to unravel the circumstances surrounding the breach.
Former Minister of Interior Lt.-Gen Abdulrahaman Dambazau said last night on television that many of the Boko Haram commanders in the facility had been there for 10 years.
He added that he was told that those men were undergoing deradicalisation being coordinated by the office of the National Security Adviser (NSA).
Gen. Dambazau insisted that people must be held accountable for the attack.
He accused security agencies of working at cross purposes, claiming that since there was an intelligence report of an impending attack on the facility, it should have been foiled.
It occurred on the same day President Muhammadu Buhari’s advance security team was attacked in Katsina.
President Muhammadu Buhari, who visited the Centre, slammed the failure of intelligence.
He directed the authorities to provide him with a comprehensive report.
The President was briefed by the Permanent Secretary, Ministry of Interior, Dr. Shuaib Belgore and the Controller General of Nigerian Correctional Service, Haliru Nababa.
He was shown the bombed-out section and the records office that was set ablaze.
Dr Belgore said the invaders launched an attack on all cells in which Boko Haram terrorists were held.
The President was informed that none of the 63 terrorists could be accounted for, but that there were backup records.
President Buhari asked: “How did the defences at the prison fail to prevent the attack? How many inmates were in the facility? How many of them can you account for?
“How many personnel did you have on duty? How many of them were armed? Were there guards on the watchtower? What did they do? Does the CCTV work?”
After inspecting some of the points impacted by the attack, President Buhari spoke to reporters, expressing disappointment with the intelligence system.
“I am disappointed with the intelligence system. How can terrorists organise, have weapons, attack a security installation and get away with it?”
The President, accompanied by Secretary to the Government of the Federation Boss Mustapha and Chief of Staff Prof Ibrahim Gambari, said he expected “a comprehensive report” on the incident.
NCoS spokesman, Mr Abubakar Umar, said the Centre has a capacity of about 940 inmates, but 994 inmates were in the facility when the terrorists struck.
According to him, the 443 who escaped have been recaptured, bringing the number of inmates in the facility to 578.
Among those who escaped, Umar said, are 64 suspected Boko Haram members, which brings to 416 the number of inmates on the run.
Among notable personalities in the Centre are suspended Deputy Commissioner of Police, Abba Kyari, former Plateau State Governor Joshua Dariye and his Taraba State counterpart Jolly Nyame, both of whom were granted a pardon.
Convicted pension thief Abdulrasheed Maina and former House of Representative member, Farouk Lawan are also in the facility.
Umar said in a statement: “The attackers broke into the Medium Security Custodial Centre, Kuje using explosive devices through the main entrance and the fence of the facility respectively, killing personnel of the NCCDC attached to the Custodial Centre and leaving three personnel of the Nigerian Correctional Service seriously injured.
“Four inmates died and 16 inmates sustained various degrees of injuries and are being treated. Efforts are ongoing to recapture all fleeing inmates.”
He added that Kyari and other VIPs did not escape.
“They are presently in custody, hale and hearty,” Umar said.
The spokesman said there were 38 military personnel on ground during the attack, in addition to policemen, men of the Department of State Services (DSS) and armed prison staff.
“Some of the attackers were killed while some escaped with gunshot wounds.
“We, therefore, appeal to hospitals and other medical institutions and practitioners to report anyone that comes to them for treatment for gunshot injuries to the nearest law enforcement agency,” he said.
A breakaway terror group, the Islamic State of West Africa Province (ISWAP), claimed responsibility for the attack.
In a video clip last night, the group showed some of its men shooting their way into the custodial centre.
The terrorists were marching in groups while vehicles and buildings were on fire in the 38-second footage.
An elderly man dressed in native attire also joined the young men who were shouting on top of their voices.
The Islamic State’s A’maq Agency released the video with the caption in Arabic language: “Fighters of Islamic State attacked Kuje prison in Abuja yesterday (Tuesday) and succeeded in freeing dozens of prisoners.”
Malam Tukur Mamu, the negotiator between the terrorists holding the Abuja-Kaduna train attack victims hostage and the government, believes the same group of terrorists were responsible for the Correctional Facility attack.
Mamu, the media consultant to Sheikh Ahmad Gumi and publisher of Desert Herald newspaper, said in a statement that he shared intelligence on the planned attack with a committee set up by the Chief of Defence Staff (CDS), General Lucky Irabor.
Mamu said the terrorists launched the attack to free their comrades due to the Federal Government’s failure to heed their request to free 10 of their comrades in exchange for the 50 kidnapped train passengers.
According to him, the terrorists initially demanded the release of 51 of their colleagues, but after negotiations, the number was primed to 10.
“Now, they have not only carried out another attack, they have also succeeded in releasing dozens of their members, which would have been averted if an action had been taken to give them only 10 and secure the release of the train victims,” Mamu said.
He confirmed a fresh threat by the terrorists to start killing the kidnapped passengers, saying they had planned to begin killing the victims by Tuesday.
He said he pleaded with them to allow room for the victims’ families to negotiate their release, which they granted and extended the threat deadline till Wednesday.
“But sadly as of today (yesterday), Wednesday, which is the deadline they gave, there is no word from anybody.
“I have nevertheless sent words to them to reconsider their threat and allow family members to reach out to them.
“On the threat to attack targets and other facilities of interest like the Kuje Correctional Centre attacks, I shared that intelligence with the security agencies and the committee that was constituted by CDS Gen. Lucky Irabor.
“I can confirm without a doubt that the Kuje Correctional Centre attack was executed and coordinated by the same group that attacked the Abuja-Kaduna bound train because they gave indications of imminent attacks to that effect which I shared.
“For the records, they requested for the release of 51 of their members. But through the power of dialogue and engagement I was able to singlehandedly scale that number to only 10 and communicated with audio backing the development to the relevant authorities.
“There was an unnecessary delay on giving them even precise feedback by the government and now they have not only succeeded in carrying out another successful attack that indicts the nature of our intelligence and capacity to respond promptly but has also succeeded in releasing dozens of their members which would have been averted if an action had been taken to give them only 10 and secure the release of the train victims.
“In all this risky, painful and frustrating engagement which government is yet to acknowledge and appreciate I have more than 100 documented audios that I shared with the relevant authorities.”
Mamu said was withdrawing from his role as negotiator given “the current sad development at the highest official level of government”, adding that he was being threatened.
“I am formally announcing my withdrawal completely from this service and to announce to the world that my life is also being threatened,” he added.