Inmate tried to strangle prison guard with towel

A US prison guard was almost killed after an inmate attacked him from behind and attempted to strangle him with a towel.

The unprovoked attack occurred in a section of Florida's Falkenburg Road Jail that houses about 72 inmates.

Surveillance cameras captured the attack on Hillsborough County detention deputy D Hernandez by Kiondre Zachary, 22, on Tuesday afternoon.

It is not known what caused Zachary to attempt to strangle the prison guard with a towel.

Vision of the attack led retired detention deputy Nelson Birch to relive a similar brush with death he had at the jail.

Mr Birch's neck required 17 stitches after it was sliced by an inmate in 2007.

"My white shirt was scarlet, I bled quite a bit," Mr Birch told WFTS.

"I'm sure he'll make it but even to this day I go to counselling, and I was diagnosed with PTSD."

Mr Birch did not even realise he was attacked by the inmate until he yelled: "I cut you man."

Mr Hernandez suffered a twisted ankle, bruised knee and abrasions to his neck during the attack.

Zachary, who was being held in remand on a burglary charge and is now facing a new charge of aggravated battery on a law enforcement officer, was uninjured and has now been transferred to an isolation cell.