Visitors attending Festival Too in King's Lynn this year will be subject to bag searches and metal detector checks.
Organisers have said plans to place these checks at all entry points into the Tuesday Market Place were made before the Manchester terror attack.
The security measures were introduced to ensure crowd safety, with past events attracting nearly 12,000 people.
A Festival Too spokesman said: 'All of the committee send out their deepest sympathy to the city of Manchester and all those families affected by Monday evening's tragic events.'
Festival Too will run for three weekends from July 1 to July 15, with huge crowds expected for Busted's performance on the final night.
The committee will be asking the public to donate £1 in the bucket at this year's event to goes towards the £85,000 needed to put the event on.
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