In pictures: Dramatic scenes from Braehead police training exercise

The multi-agency action – held throughout Tuesday evening at Intu Braehead – had been planned since early last year, Police Scotland said.

The exercise was not in response to any recent incident or specific threat, said assistant chief constable Bernard Higgins.

He said: “The emergency services and partners plan extensively for a wide number of challenging situations from naturally occurring events caused by the weather to significant industrial accidents or criminal acts.

“This exercise has been in the planning for a year and specifically focuses on a major firearms incident and will test how our specially-trained armed officers respond alongside other emergency services at a crowded place, which for the purposes of this scenario, is a major shopping venue.

“I must reiterate that this exercise is not in response to recent events in Paris or any threat to any specific location.”

He said training exercises allowed authorities to ensure the response to a genuine incident was current and ran as “efficiently and effectively as possible”.

“Whilst everyone in Scotland hopes we never have to activate any major incident plan, it is important that we are ready to do so should the need develop. This proactive approach to preparedness helps to protect Scotland’s status as a safe and secure country,” he added.

Gary Turnbull, general manager for the shopping centre, said: “The emergency services do an extremely important job keeping the public safe.

“This training, planning and preparation to deal with all eventualities is essential and we had no hesitation allowing them to use our facilities for their exercise while the centre was closed.”