Police were called to the Royal Mail delivery office in Brighton to reports a man had a gun.
Sussex Police sealed off North Road this morning (May 26), after a call came in at 10.45am that a man had 'attended Brighton Royal Mail delivery office with what was believed could be a gun'.
Officers said they located the man's car which was parked in North Road, and closed the road as precaution while they searched it.
One man has been arrested on suspicion of possession of a firearm, according to police.
The road reopened at 12.10pm.