Jails where terrorists are held need better management, prison officers say.
Failed bomber Hussein Osman's prison cell was set on fire
Prison Officers Association chairman Colin Moses said more needed to be done to prevent attacks on offenders or the radicalisation of other inmates.
His comments follow two incidents at Durham's Frankland Prison, the most recent of which saw a 21/7 bomb plotter's cell set alight.
Mr Moses said extra investment was needed to cope with the presence of "zealots" in prison.
The Prison Service has launched an investigation into the fire at Frankland on 22 July.
Hussain Osman, 28, serving a life sentence for his part in the failed attacks on London's transport network, is believed to have returned to his cell to find it ablaze.
A Prison Service spokesman confirmed there had been a "small cell fire" at the jail, but said no-one was hurt in the incident.
Mr Moses said prison infrastructures need to change to cope with the presence of extremists.
He said: "Any terrorist is likely to be a victim in prison and we must remember that they too have families and often very strong beliefs.
"These terrorists are different. We've never had suicide bombers in prison before. What we need is to put the proper investment into prisons so we can protect those sentenced by the courts.
"We must use prison intelligence to be aware of racial tensions between different ethnic groups and also to combat the possible radicalisation of other prisoners."
Earlier this month al-Qaeda plotter Dhiren Barot, also serving a life sentence at Frankland, was badly injured in an attack at the prison.
He spent five days in Newcastle's Royal Victoria Infirmary with what were believed to be scalding injuries.