Hertfordshire Constabulary is reviewing their policy for crowded places and public events after the horrific terror attack in Manchester.

At least 22 people were killed, including girls aged eight and 18, when a suicide bomber targeted the Ariana Grande concert at Manchester Arena.

Hertfordshire police announced the review but have reassured the public saying there was no specific threat to the county.

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Chief constable Charlie Hall said: "On behalf of everyone in the constabulary I would like to send my sincere condolences to all the victims and their families.

"My thoughts remain with everyone who has been affected by this deeply shocking act.

Watford Observer:

Flowers left for the victims

"I would once again encourage people to remain vigilant and report any suspicious activity or behaviour to police straight away."

Police in Greater Manchester confirmed that at least 59 people were injured in the attack with many of the wounded suffering shrapnel wounds.

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A 23-year-old has been arrested in South Manchester in connection with the incident.

Ariana Grande announced that she was cancelling the rest of her world tour.

Detective superintendent Glen Channer, head of the Eastern Counter Terrorism Intelligence Unit, added: "The security and intelligence services are dedicated to keeping people safe and communities can be confident that, together, with our partners, eastern forces are continually working hard to safeguard the public.

"As always we rely on the support and co-operation of our public in the fight against terrorism and at this difficult time would remind people that they can report concerns or any suspicious activity they may witness to the confidential police hotline."