Armed officers will be deployed across Norfolk over the coming days as the UK terror threat is raised to its highest level.
It comes after 29 people were left injured in south-west London on Friday following a bombing on the Tube during rush hour.
The UK terror threat level has now been raised to critical, meaning an attack may be imminent.
Norfolk Police said specially trained officers were sent to Norwich train station during rush hour on Friday evening to offer 'visible reassurance' to commuters.
And temporary assistant chief constable Paul Sanford said more armed officers will be patrolling across the county over the coming days.
He said: 'Norfolk is a safe county and there is no intelligence at this time to suggest that it will be targeted.
'However, I would continue to ask the public 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, we would rather investigate concerns which come to nothing, rather than hear an incident could have been prevented.
'In response to the threat level being raised, members of the public will see an increased presence of armed officers at key locations across the county over the coming days.'
Mr Sanford added: 'Our thoughts are with the people injured by the explosion and all the emergency services involved in caring for them.'
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