Police Scotland has staged a mock terror attack at a shopping centre in Renfrewshire.

Two masked and hooded men "opened fire" in a packed bus stop at Intu Braehead on Tuesday evening.

A number of actors were lined up against a wall by the men in what appeared to be a mock execution.

Police Scotland said the operation had been planned since early last year and was not in response to any specific threat or incident.

Chief constable Bernard Higgins 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".

Police previously used Longannet Power Station in Fife to train for the kidnapping of a government minister.

Mr Higgins added: "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.