Three prison officers have been injured in a disturbance at the Shotts maximum security jail in Lanarkshire.

The incident is the second at the prison in less than a week.

The unrest broke out at about 1630 GMT on Tuesday in a special unit which houses newly arrived prisoners who are having difficulty adapting to the prison regime.

Any injury to staff is a matter of serious concern Scottish Prison Service spokesman

Three guards have been taken to Wishaw General Hospital for treatment after being injured.

It is believed that they may have been stabbed, although their injuries are not thought to be life-threatening.

A Scottish Prison Service spokesman said the disturbance had been confined to the special unit located within the prison.

"There is a maximum of half a dozen prisoners involved," he said.

"There are reports that three staff have been injured but we are not able to say how serious their injuries are at this stage.

The prison has seen unrest in the past

"Any injury to staff is a matter of serious concern."

Prison authorities said there were no hostages involved.

The cause of the disturbance is not yet known and a negotiating team is at the prison aiming to ensure a peaceful end to the situation.

An investigation was launched last week after a 19-hour protest at the jail.

About 80 inmates were involved in the disturbance, in which a prison officer suffered a broken leg.

The prison, which is sited near the village of Shotts, has been affected by unrest in the past.

Serious crimes

There was a stand-off in April last year between prisoners and authorities after an electrical storm cut off supplies to the facility.

All prisoners at Shotts are serving a minimum of four years, while many have been sentenced to between 10 years and life for serious crimes such as murder.

The prison is also the base for Scotland's National Induction Centre, where all inmates sentenced to 10 years or more serve their first 12 months.

The prison, which was built in 1978 and can hold up to 560 inmates, is currently running just below capacity.