Professor David Capitanchik, terror expert from Robert Gordon University in Aberdeen, told Scotland on Sunday that the blast, which was heard several hundred yards away and has raised the possibility of an al-Qaeda style training camp operating in the area, bore the hallmarks of a test run. “Terrorists get training in Pakistan, or Afghanistan, they get shown the materials and how to put the bombs together. But the critical thing is how to detonate it.” he said. “I would think they were planning for something imminent.”
Forensics officers, including counter-terrorism specialists from the Metropolitan Police and Royal Navy explosives experts, were yesterday still carrying out a fingertip search of the blast area, where it is believed several devices have been recovered.
A wide area has been closed off to the public and, on Friday, Met helicopters with thermal imaging equipment flew over the area. A tree is thought to have snapped in half during the explosion, reported to the police on Wednesday afternoon by a dog walker.
A former senior security source said: “This is somebody who is testing the viability of an explosive. They are testing out a mixture or some sort of device to see if it works.”
He added: “I think it’s pretty clear this is a big concern. Ever since Mumbai (a terrorist attack on the Indian city], when gunmen entered the building carrying explosives, we have been concerned about that.
“So someone testing devices to see if they will work is a worry.”
He said the investigation would focus on specific hallmarks of terrorist activity.
“What they will be looking for is any traces or fragments which they can analyse to what nature of explosive it is – commercial, military or homemade.
“Depending on which it is and what debris they can find, they may be able to trace it back to who would use this, who would have exploded it.”
Chief superintendent Calum Murray, divisional commander, Argyll, Bute and West Dunbartonshire, last night maintained that terrorism-related activity could not be ruled out.
He said: “The location of this explosion poses a significant challenge in terms of the size of the area and the terrain we are searching.
“This is a meticulous and painstaking operation which is understandably taking some time.
“It is only right that we carry out the most thorough of investigations and avoid speculating on the nature of this incident until we have thoroughly considered and analysed any potential evidence we may find. Police are following a number of positive lines of enquiry into the circumstances surrounding the explosion on Wednesday afternoon.
“The area remains cordoned off and it will take considerable time to search the location.”