Reports of a man brandishing a firearm led police to cordon off a road which passes through Borehamwood and Radlett this afternoon.
Officers were called to sightings of a man acting suspiciously, in Theobald Street, at about 3.15pm.
Police were present at all junctions along the road, which was closed off to motorists and pedestrians.
A police helicopter was also dispatched to search the area for the man.
A police spokesperson said: "Police were called to reports of a man acting suspiciously on the road.
"Officers were in the area working to trace the individual reported. No individual was found and there was found to be no threat to the public, so the search was concluded."
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