An assistant garda commissioner has warned gang bosses that 'nobody is untouchable'.

Speaking to the Irish Examiner, Commissioner Michael O'Sullivan said the Regency Hotel shooting was 'a Veronica Guerin moment' for Ireland.

It comes as Prison Visiting Committee reports from 2015 show a rise in the number of inmates under protection.

Mr O'Sullivan has warned the bosses of the Kinahan cartel that like John Gilligan's gang before them, nobody is untouchable.

"Some groups have made a lot of money, but they are in the minority,", he told the paper.

"Some groupings have lost a lot."

"We are constantly undermining, dismantling, and arresting criminal groupings. We are seizing greater quantities of drugs" he added.

Seven people have been killed so far in the ongoing feud between the Kinahan and Hutch gangs.

Tributes have been paid to Sunday Independent journalist Veronica Guerin, on the 20th anniversary of her murder yesterday.

The Dublin woman was sitting in her car at traffic lights on the Naas dual carriageway on June 26th 1996, when she was shot six times by one of two men on a motorbike.

Archbishop of Dublin Diarmuid Martin told a mass to remember Ms Guerin, and that her courage and integrity stand as an example to many others.

Increase in protected prisoners

The Irish Prison Service says the majority of protection prisoners are there at their own request, and can be described as in 'voluntary' separation from other prisoners.

The number of protection prisoners in Mountjoy Prison rose to 133 in October last year - up from 119 in July.

"More than one in four prisoners was reported to be under a restricted prison regime", the report says.

"Concern is expressed for the mental health of prisoners in the protection system and the Committee has requested that this situation be reviewed as a priority."

While in Cloverhill Prison, the Visiting Committee report states: "There continues to be a substantial increase in the number of prisoners requesting protection on committal to prison."

"This can be a significant percentage of the prison population on any given day."

"This continues to place a massive strain on the prison's resources, and can be a logistical nightmare."

It adds that all of these prisoners have to be segregated, and within the segregation there can be further segregation.

"This leads to a restricted prison regime, including limited access to education, and on occasion a limited amount of out of cell time."

The report also finds that the growth of protection is "a consequential reflection of the gang culture in society."

"As we highlighted previously external gang feuds affiliations do not stop at the gate of the prison when people are committed to prison."