Police are investigating after a haul of home-made knives was discovered at a Sheppey prison mosque following a gang fight.
Three inmates suffered injuries from the makeshift weapons during a mass brawl that broke out in the gym at HMP Swaleside.
Searches later revealed several improvised knives found hidden under prayer mats in the prison mosque.
The category B jail, which can hold more than 1,100 prisoners, is said to have the largest Muslim population of any prison in the country.
Dave Todd, Prison Officers Association chairman for Swaleside, said there were about 15 of the weapons discovered "dotted around" the religious site.
"They are using religious views to promote violence. It is gangs hiding behind religion..." - Dave Todd, Prison Officers Association
He said the knives are often made by melting razor blades into plastic tooth brushes or by filing down bits of metal.
Mr Todd said: "It is all to do with the gang culture and gangs wanting to carry on issues from outside the walls.
"Whatever happens outside is then reflected inside the walls.
"There was a fight between the two gangs the previous week in the gymnasium and it was payback for that.
He added: "They are not devout Muslims. They are using the religion as cover.
"They are using religious views to promote violence. It is gangs hiding behind religion."
A Prison Service spokesman said: "Staff at HMP Swaleside responded quickly to resolve an incident.
"Violence in prison is not tolerated in any form and this incident has been referred to the police."
The injuries suffered by the three prisoners on Friday, November 22 are not believed to have been life-threatening.
No prison officers were hurt in the incident, but Mr Todd said that "without a doubt" Sheppey's prisons are becoming more dangerous places to work as the level of violence is escalating.
His claims were backed up be an Independent Monitoring Board report into the Brabazon Road site that was made public recently.
It found the level of violence has continued to be "unacceptably high".