The Minister of Defence made the revelation on Wednesday in Abuja, while addressing reporters.
Magashi said there are strong indications that terrorists invaded the facility to free their members being held in detention.
He explained that the Federal Government is working hard to ensure that other fleeing inmates were being recaptured and kept back in the facility.
“Most likely, they are Boko Haram because we have a sizeable number of Boko Harams that are in detention,” the minister said.
“Presently, we could not locate any of them. I think there are about 64 Boko Haram (members) in prison, they have all escaped.”
Noting that the situation is under control, he said the correctional centre could accommodate 994 prison inmates.
The Defence Minister added that the government has been able to track down 600 inmates who have been recaptured.
Magashi added, “We are trying to see what we can do to ensure that all the escapees are brought back to the prison yard. I think the prison is an accommodation for about 994 inmate escapees.
“We have 600 already inside now and many people are being captured and brought back to the prison. Maybe by the close of the day, more would have been captured. I think everything is under control.”