There are reports of damage to accommodation areas in the jail
A prison officer has been attacked and injured during a disturbance at a jail in Kent.
The Prison Officers Association (POA) said a major incident had broken out at Swaleside Prison on Sheppey.
Spokesman Michael Rolfe told the BBC trouble began in the afternoon, during which fires were lit and the officer was attacked with a blade.
Ambulance crews treated the officer for an injury to his scalp before taking him to hospital.
Specialist staff were drafted in to quell the disturbance which continued into the evening as two inmates gained access to metal netting above the cells.
By 22:30 BST they had been removed to isolation units in the prison.
'Drink or drug-fuelled'
Mr Rolfe, who works at nearby Elmley prison, said he was in touch with colleagues at Swaleside.
He said it had been confirmed the injured officer had been attacked with a bladed weapon and had received either a stab or slash wound.
He said police and fire crews went to the jail at 18:15 BST, and Kent fire brigade confirmed it was at the scene.
"It sounds as if it's drink or drug-fuelled," Mr Rolfe said.
"There is a lot of damage to the prison," he added, saying he believed the damage to be in accommodation areas.
Staff at the command centre dealing with the disturbance had told Mr Rolfe fires had been lit and telephone equipment broken.
The POA blamed the disturbance on staffing shortages
A spokeswoman for the Ministry of Justice said only two inmates had been involved in the disturbance, but she confirmed an officer had been attacked.
The officer had been treated in hospital and later discharged, she added.
'Not enough staff'
In 2011, several staff members were injured during a disturbance involving eight inmates.
And last week a report on the jail said some prisoners were too scared to leave their cells for fear they would be assaulted.
An unannounced inspection of HMP Swaleside found staff shortages were "affecting every area of the prison".
A report on the jail said some prisoners were too scared to leave their cells
Mr Rolfe linked staffing numbers to the latest disturbance, telling the BBC: "This is the problem with cuts to the service. We don't do the security checks we used to do.
"They're not so thorough and they're not so frequent and unfortunately this is what happens. There are not enough staff to do it."
In response, the Ministry of Justice spokeswoman said there was no link to staffing.
HMP Swaleside is a category B prison and holds about 1,100 inmates.