The security forces have been placed on heightened alert after receiving intelligence of a dissident republican plot to attack a Northern Ireland Army base.
Security chiefs are concerned that a mortar attack on one of the bases is imminent and have placed all Army personnel on high alert.
It is understood military personnel were briefed about the developments over the weekend. An MoD source told the Belfast Telegraph: “We have all been placed on a high state of alert and have been warned that a mortar attack on any one of the barracks is imminent.”
The MoD declined to discuss the latest threat saying that matters of security in Northern Ireland are a matter for the police. He added: “For obvious reasons we do not discuss operational security.”
Police said: “We do not comment on specific intelligence matters and no inference should be drawn from this.”
The security forces have been on heightened alert since the March murders of two soldiers at Massereene Army barracks in Antrim and police Constable Stephen Carroll in Craigavon.
The dissident republican terror threat remains “severe” and all three dissident terror groups — the Real IRA, Continuity IRA and Oglaigh na hEireann — have intensified their activities in recent weeks.
Oglaigh na hEireann was behind a 600lb bomb attached to a command wire stretching into the Republic which was defused by the Army in south Armagh last month. Security sources said the bomb was one of the most sophisticated to have been assembled by any of the dissident terror groups in recent years.
It is understood they were investigating whether a former veteran Provisional IRA bomb-maker from Belfast had defected to one of the dissident organisations and was helping to improve its bomb-making capability.
The Continuity IRA is believed to be behind two nights of violence on the streets of Lurgan last month when hijacked burning vehicles blocked the Dublin-Belfast rail line. The disturbances followed the jailing of three Continuity IRA men for 15 years in connection with a mortar bomb plot aimed at killing police officers.
In Londonderry the Real IRA left bombs at the homes of relatives of a Catholic police officer. Catholic recruits to the police remain among the prime targets of dissident terror groups. A bomb exploded outside the home of the policeman's parents in the Shantallow area of the city. The dissident terror group then left a second device outside the same police officer's sister's home in the Kylemore Park area of Derry.
No one was injured in the Shantallow blast but a car was damaged. Several families were forced to flee their homes close to the second house targeted in Kylemore Park.
The Real IRA has also been responsible for at least six so-called ‘punishment’ shootings in Derry over the last few months.
In August the Real IRA took over the south Armagh village of Meigh, where armed men wearing masks set up a roadblock to stop traffic. During the incident a police mobile patrol spotted the Real IRA unit but withdrew from the village fearing that their presence would provoke a gun battle.