Semtex explosive formerly belonging to the Provisional IRA was used in a terrorist attack on police officers in Northern Ireland at the weekend, marking a dangerous escalation in the capabilities of so-called ‘dissident’ republican groups intent on reigniting the province’s long and bloody conflict.

Two police officers narrowly escaped death or serious injury on Saturday night in the border town of Lisnaskea, Co Fermanagh, according to Paul Leighton, the Deputy Chief Constable of the Police Service of Northern Ireland (PSNI).

The most alarming element of the rocket attack was the detection of Semtex – an explosive imported into Ireland in vast quantities in the mid to late 1980s by the Provisionals as a gift from Colonel Muammar Gadaffi of Libya.

The Provisional IRA was meant to have decommissioned its stockpiles of weaponry in what had proved to be the most difficult part of the peace process to accomplish, with an independent group led by the retired Canadian General John de Chastelain overseeing the operation. The decommissioning process was formally concluded in 2005.

The main loyalist terrorist groups which followed the Provisional IRA’s lead and declared their campaigns of violence over have never decommissioned their arsenals, but never possessed the same quantities or calibre of weaponry.

The admission by the police that Semtex was used confirms a long-held suspicion that the Provisionals never surrendered all their weaponry and suggests that some of its members are now actively assisting the dissidents – in groups such as the Real IRA and the Continuity IRA – or have crossed over into their ranks, taking with them resources previously controlled and held by PIRA.

Mr Leighton said the rocket attack was the latest in a series of attempts by dissident groups to kill police officers, the main objective of republican terrorists.

He said: "It is significant in the sense that there was Semtex in the explosive charge. It did not go off but there was Semtex there. Where it came from, I don't know.

"It is similar to devices that used to be used in the province by other groups.

"But when it [the Semtex] was passed over to different groups, how it came to be in their possession, I don't know at this point in time."

Mr Leighton said that three officers were on patrol in Main Street, Lisnaskea, shortly after 11pm on Saturday when the attack was launched.

Two officers standing on the street and a third colleague sitting in a police vehicle nearby were targeted when republicans armed with an improvised rocket launcher jumped from a passing car and launched the device.

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