Senior security sources on both sides of the border believe that dissident republicans have succeeded in buying “heavy” weapons from terrorist army-dealing mobsters in south east Europe.

A tip-off, in the wake of a report circulated by Europol to police forces throughout the EU at the weekend, has led to fears by the PSNI that rockets and assault rifles may be used shortly in attacks on police officers in Northern Ireland.

It is understood gardai have also been made aware of the latest terror threat. It is understood a major review of patrolling schedules is now currently under way in some flashpoint areas, including Belfast, Tyrone and south Armagh, where failed bomb attacks have been mounted by dissidents in recent weeks.

It was also reported yesterday that the PSNI has warned officers to stay out of Ardoyne at night in soft-skinned patrol cars after intelligence revealed dissidents have got their hands on a heavy calibre sniper’s rifle.

The Sunday World reported an alert went out on Friday after intelligence flagged up a serious threat to life posed from the Real IRA.

The Republic’s Justice Minister Dermot Ahern and other EU justice ministers have expressed concern over reports concerning the “apparent availability” of heavy weapons to subversives, which emerged at an EU summit in Brussels, last week.

The meeting was followed by the weekend call by Europol — the EU international security force — for an integrated approach to a crackdown on efforts by terror groups, including drug gangs and republican dissidents, to acquire assault rifles and explosives.

Soren Pederson, a spokesman for Europol, revealed yesterday they are seeking to “further enhance intelligence and restrict the flow of illegally trafficked weapons into and out of Europe”.

He said: “Organised crime groups, and street gangs, are routinely using firearms in populated areas, posing a significant threat to the general public and law enforcement personnel.”

“Although handguns are generally their weapon of choice, there has been a marked increase in the use of heavy firearms, fuelled by the fact that a Kalashnikov assault rifle, or a rocket launcher, can actually be acquired for between €300 to €700 in parts of the European Union.”

A Europol officer also revealed they were aware that that certain ruthless suppliers in south east Europe are currently meeting a demand for illegal weapons.

He said: “The establishment of firearms ‘pools’ in major cities in Western Europe has significantly increased the local availability of weapons to criminal hubs.”