Armed police have been scrambled to two incidents in the same part of Brighton.
A member of the public spotted a man with a gun near The Level at about 3.50pm.
Armed officers were already searching an area near the Vogue Gyratory in Lewes Road after three people had been reported to behaving suspiciously in a car.
The Sussex Police helicopter was sent to help the search.
It is understood an abandoned car has been found.
Anyone with information is asked to call Sussex Police on 0845 6070999.
*Did you see the police operation? Call The Argus on 01273 544520, email ben.parsons@theargus.co.uk or leave your comment below.
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