Northern Ireland: Terrorist attack foiled in Londonderry just minutes before mortars due to be fired at police station

'Mass fatalities' avoided in major coup for security forces as three men arrested

Police forensic officers examine a car in which four mortar rounds were found in Londonderry (PA)

An attempt by dissident republicans to stage a mortar attack in a built-up area of Londonderry could have caused multiple casualties, according to both police and local representatives.

But the attack was foiled in what appeared to be a clinical interception by police, who arrested three men just minutes before it was scheduled to take place.

Officers rammed a van carrying four primed mortars as dissidents were on their way to attack a police station. The security operation is regarded as a coup for the security forces, who evidently had clear intelligence of the terrorist plan.

Police Chief Superintendent Stephen Cargin said: “They were destined for a police station. It was a reckless attack. They were prepared to drive through a built-up area of the city to carry out this attack and cause mass fatalities.

“These devices were primed. They are crude home-made devices and there is no way people who made these bombs would be certain they would have hit their target. There would have been mass murder of police, and serious damage to property.”

Although there was huge relief that the attack was averted, it was tempered by the fact that splinter groups such as the Real IRA have been expanding their armoury with weapons such as mortars and rockets.

Such organisations are small and, as the Londonderry incident indicates, have been heavily infiltrated by the security forces, who use both informants and sophisticated surveillance methods to penetrate them.

While many of the terrorist operations go wrong, their campaign continues and can occasionally result in fatalities. The last of these came several months ago when prison officer David Black was shot dead as he drove along a motorway to work.

Deputy First Minister Martin McGuinness of Sinn Fein said he wanted to pay tribute to police “for preventing what could have been a terrible loss of life in an attack which was clearly designed to damage the peace process.”

He added: “Increasingly people are providing information which is the proper thing to do so that we can thwart the efforts of those who would try to destroy the peace that is so admired throughout the world.”