POLICE are using tactics pioneered during the Ulster Troubles to try to prevent jihadi terrorists killing frontline officers on Scotland's streets, the Sunday Herald can reveal.

Police chiefs have warned officers in the wake of the Paris Attacks that they are at a heightened risk of being targeted by Islamic extremists. There are fears terrorists plan to "wipe out" police with deadly car bomb plots, according to senior security sources.

Police insiders say Scots officers are now checking under their vehicles for explosive devices after being urged to be "vigilant for their personal safety".

The new security measures mirror precautions taken by the RUC in Northern Ireland during the Troubles, when officers searched their cars, avoided taking the same route to work, and did not wear their uniform to and from the station in order to hamper IRA assassination plots.

A police source, based at a Glasgow station, said: "When I'm leaving the house for work, and after my shift, I've taken to checking under my motor.

"I don't climb straight in, I get down on the ground and have a good look at the underside of my car for anything that looks dodgy or suspicious.

"We're at the stage where we can't be too careful."

Tensions are running particularly high among Scots officers as they fear they may be the target of an attack similar to that which was narrowly averted in Belgium.

Authorities said a dozen searches in Verviers led to the discovery of four military-style weapons, including Kalashnikov assault rifles.

Several police uniforms were also found during the raids, which could have allowed the suspects to pass themselves off as police officers to launch an attack.

The insider added: "I know colleagues who have adopted some of the practices used by police in Northern Ireland during the 1980s.

"Some won't hang out their uniform on the washing line for fear of 'advertising' that they are police, others are leaving their own cars at home and travelling to work on public transport.

"Meanwhile, others are making a conscious decision to mix up their daily routine, maybe taking a different route to work, or taking the bus instead of the train."

There is also growing concern that a terror attack carried out in Scotland would be perpetrated not by an organised cell but a "lone wolf".

But senior officers admit the job of identifying individuals is "extremely challenging".

Internal advice has been issued to officers across Police Scotland, including warnings about putting personal sensitive information on social networking sites such as Facebook, Twitter and Instagram.

Another officer, who did not wish to be named, said: "We've been told to make sure we know exactly who we are accepting friend requests from on Facebook, ensure the profile with your pal's name is really your pal and not someone on a fishing expedition.

"The raised threat level means officers have to be extra vigilant in everything they do.

"We have to be aware of who is around us at all times, whether its making your way home from work or picking the kids up from school, we have to be careful.

"It's also about challenging people you don't recognise at stations and asking for ID.

"Most colleagues I've spoken to are being extra cautious - we have to take the threat seriously."

More than 300 full and part-time police officers were killed during the Northern Ireland Troubles. Many were targeted while off duty, or killed going about their daily routine.

Deputy Chief Constable Iain Livingstone, said: "Our officers are used to confronting risk and are highly trained to protect both the public and themselves.

"However, policing can be a dangerous job so it essential that in keeping people safe we also ensure we keep our officers and staff safe.

"We have therefore updated our advice on their personal safety."

The warning to police comes amid MI5 fears that extremists are planning an attack similar to that of Fusilier Lee Rigby, killed in 2013 by two fanatics as he walked near his Woolwich barracks.

Officers are being advised to keep a low profile outside of work, and be aware of anything that could put them at risk.

Drummer Rigby was not wearing his uniform when he was attacked, but a Help for Heroes hooded jumper.

DCC Livingstone added: "Police Scotland will continue to work with our partners in the community and in the counter terrorism network across the UK to keep people safe.

"While there is no specific threat to Scottish Communities we must not be complacent, as Scotland is not immune from the threat posed by terrorism.

"Dialogue is ongoing with community and faith leaders.

"There are strong community relations in Scotland and the links between the public and the police are excellent.

"I would urge all communities to remain alert."

Head of Europol, Rob Wainwright, said the need for tightened security across Europe highlighted the terrorist threat.

He said: "We're dealing with multiple thousands of potential terrorists."