Norfolk’s chief police officer has urged people to go about their daily business, while being alert to suspicious activity.
It comes as police respond to the national terror threat level being raised to critical.
Armed officers have been deployed to key locations in both counties, in particular crowded areas with high footfall such as the city centre, to provide visible reassurance.
It comes after the Joint Terrorism Analysis Centre raised the threat level last night – meaning an attack not only remains highly likely but a further attack may be imminent.
Chief Constable Simon Bailey said: “The public would expect us to respond appropriately to this raised threat level and the deployment of armed officers is our primary response to this.
“Norfolk is a safe county and this additional policing is about providing a visible reassurance to the public.
“I would encourage anyone who sees those officers carrying out patrols to approach them, speak to them and support them because when incidents happen like those witnessed in Manchester and in Westminster, it’s those officers who rush to the scene to help, at a time when everyone else is trying to get away. I know they would appreciate the support.”
Military personnel are not currently being deployed in joint patrols with police officers in crowded places – but the threat assessment is continuously under review.
Officers are also reviewing security plans for a number of events in the coming weeks.
Mr Bailey added: “I would urge people to go about their daily business as usual, but be extra vigilant and report anything you think looks out of place.”
Members of the public are asked to remain calm but alert – if you see anything which causes you concern, then call the police immediately. Look out for anything that seems out of place.
Latest guidance on recognising the terrorist threat and remaining vigilant can be accessed via www.nactso.gov.uk
To report any suspicious activity or behaviour call 0800 789 321 or in an emergency dial 999.