POLICE investigating a foiled mortar bomb attack in Derry/Londonderry have arrested a fourth suspect.
The 31-year-old man was arrested in the city on Tuesday as part of the ongoing investigation.
The four suspects are currently in custody at the Antrim serious crime suite being quizzed about the bomb find.
Belfast Daily revealed on Monday that one of them is Thomas Ashe Mellon, who was once charged with bomb making offences in Co Donegal.
And another suspect is, according to republican sources, Seamus McLaughlin. A third is Gary McDaid.
Mellon and McLaughlin are from the Creggan district of Derry. All three are believed by police to be leading members of the ‘New IRA’ in Derry.
During Sunday night’s covert operation, four live and primed mortars were uncovered and three men arrested after police stopped a van bearing Republic of Ireland number plates as it headed into the city centre on Sunday night from the direction of Letterkenny, Co Donegal.
A motorbike, which police believe was the ‘scout’ vehicle for the attack, was also stopped as it drove behind the van.
The motorcyclist was arrested along with the driver of the white van. They are believed to have been McDaid and McLaughlin.
On board the van, the PSNI discovered four live lethal mortar devices inside metal tubing welded to the floor of the van.
The roof of the van had been removed in preparation for the attack.
Police believe the intended target of the attack was Strand Road PSNI station and the van was just minutes away from the base before it was intercepted.
Belfast Daily understands the deadly discovery was made following a lengthy surveillance operation against dissident republicans in the Maiden City by MI5, the Army’s Special Reconaissance Regiment and the PSNI’s ‘C3’ Rural North Intelligence Branch.
Two men, aged 37 and 35 were arrested at the scene of the van.
In a follow-up operation, 37-year-old Thomas Ashe Mellon was arrested at a house during the planned operation.
Belfast Daily can reveal that one of them 37-year-old Mellon had previously faced a court in the Republic in 1999.
Mellon, then aged 23, appeared in the dock of the Special Criminal Court in Dublin along with 34-year-old Raymon Griffith on explosives offences.
At first the Special Criminal Court refused the Director of Public Prosecutions’ application to charge Griffiths because it had not been given enough evidence.
Griffiths was freed but re-arrested as soon as he left the court precincts in north central Dublin and taken to Bridewell Garda Station to prepare for a fresh court appearance.
He was before the court an hour later when the charge was put to him.
Mellon, of Cromore Gardens, and Griffiths, from Slievemore Park, were both charged with possessing explosive substances in the early hours of Thursday near Manorcunningham, Co Donegal.
It was alleged they had bomb making materials including: three bags of fertiliser, a black powder substance, electronic and mechanical weighing scales, graduated plastic containers, spatulas, two cut down aluminium beer kegs, gloves, overalls and a scanning radio.
Both were remanded in custody. However, the following year both were set free when the charges were withdrawn.
Following Sunday night’s interception, police said a huge loss of life had been prevented.
PSNI Chief Supt Stephen Cargin said on Monday morning that four mortar bombs were found in the van and the bombers plan was to “kill and cause casualties”.
“This was reckless. We would have had mass police casualties. I have no doubt if we had not intercepted these devices we would have been dealing with mass casualties.
“The roof had been cut out to leave a hole in the roof to allow the mortars to be fired and hit its target, a police station.
“These devices could have detonated on route to their target at any time. So the people behind this didn’t care that they were taking live mortars through a built up area of the city.
“This is a worrying development. Dissident republicans want to take us back to the past where nobody wants to go. They have nothing to offer the community.
“I can assure the community we will do everything within our power to protect the community. We thank the community for their continued support.”
SDLP Foyle MP Mark Durkan told the BBC Nolan show on Monday: “We’ve been spared an awful catastrophe”.
Several hundred people had bee evacuated from around 100 homes within the vicinity of the mortar bomb-laden van.
At one point during the evacuation, a crowd gathered and a petrol bomb was thrown at a police car but no damage was caused.
A fleet of ambulances rushed to the scene to help move a number of people with disabilities from their homes to safety.
Army bomb disposal experts were called to the Letterkenny Road area of Londonderry after the devices were discovered.The security is expected to stay in play until lunchtime until the devices are made safe.
A PSNI spokesman said: “Police are currently dealing with a security alert in the Letterkenny Road area of Londonderry, following the discovery of a suspicious object in a vehicle.
“Approximately 100 homes have been evacuated and army technical officers are at the scene.
“Detectives from PSNI serious crime branch are dealing with the incident and are linking it with dissident republican activity.”
SDLP MLA Pat Ramsey said: “This discovery of a possible viable device by PSNI this evening reminds us of those who would recklessly endanger the lives of people in this community.
“I cannot state it any stronger; I want to make it clear that the people of Derry do not want this and those behind it need to stop.
“I am calling on anyone with information to come forward and assist police with their ongoing investigations in regards to recent attacks on our community.”
Mr Ramsey said those responsible “are bringing nothing but distress and disruption to the people of this city”.
The Bishop of Derry and Raphoe Dr Ken Good also condemned planned mortar attack.
He said the incident was a throwback to “a time of division and violence”.