A major search operation is under way after a prisoner escaped from custody in Tallaght Hospital following the stabbing of two prison officers.

Gardaí say Derek Brockwell, 53, was at the hospital for treatment when he escaped.

The UK national was serving a seven-year sentence in Portlaoise Prison for armed robbery in 2012.

One of the prison officers accompanying him was stabbed in the stomach and had emergency surgery, according to a spokesman for the Irish Prison Service.

A second officer was stabbed in the hand and possibly in the face or neck during the incident at around 3pm.

A third officer was uninjured but said to badly shaken.

With the assistance of an accomplice, Brockwell made his escape from the hospital on a motorcycle.

He had been serving a life sentence in the UK for a series of armed robberies, mainly from betting shops in the London area, but absconded while on day release.

He is described as 1.90m (6'3") tall with brown hair and a broad build.

Lancashire police say Brockwell has connections in Scotland and Ireland and have described him as a dangerous individual

The Prison Service said it is now trying to establish the facts surrounding the escape. 

Director General Michael Donnellan said his thoughts are with the injured prison officers

Anyone with information on the incident is asked to contact Tallaght Garda Station on 01- 6666000, the Garda Confidential Telephone Line 1800 666 111 or any garda station.

The Prison Officers Association has called for a full review of security in relation to prison escorts.

The association said it particularly wants to know how Brockwell was allowed to leave Portlaoise Prison with the level of security he had.

RTÉ News has learned that Brockwell had previously been provided with an armed escort but this was withdrawn in the last year.

POA president Stephen Delaney has said the incident "highlights the difficult task of a prison officer every time a convicted prisoner is taken out of prison, and the potential for escape."

He is seeking a review, following what he said was a "well planned escape."