POLICE firearms officers will take part in an exercise to test their response in the event of a major terrorist attack today.

Thames Valley officers along with the military will practice their contingency plans at Carmel College near Wallingford.

The college will be used as a scenario for a marauding terrorist attack.

The exact time of the exercise is not being revealed.

Tomorrow, another exercise will take place in Hampshire, where officers will practise rescuing hostages at two buildings.

Deputy chief constable John Campbell said the operation is one of a number of "routine" and pre-planned" exercises organised across the country to test the response of emergency services.

He added: "We carry out these exercises to test contingency plans and the coordination of the response to a major incident on a regular basis. This training is not being carried out in response to a any specific threat.

"Since August 2014, the threat to the UK from international terrorism has been graded as 'severe', meaning an attack is highly likely. As such I want to take this opportunity to remind the public to remain vigilant.

"We depend on information from the public. They can be our eyes and ears and help keep themselves and communities safe by reporting suspicious activity."

Mr Campbell said the surrounding communities of Carmel College may hear gunshots and see some activity in the area during the exercise.

The deputy chief constable said in the unlikely event of an attack, members of the public should remember three simple steps: run, hide, and tell the police.