A quick-thinking member of Herefordshire Council's street cleansing team called police when he found what he thought was a hand grenade in a litter bin.
Paul Parsons, who works for Herefordshire Council's contracting partners Amey, saw what he thought was a hand grenade in the bin in a layby near to the Tram Inn on the A49 and immediately called his Street Scene supervisor Tom Hill.
Tom said: "The police were called and, within 15 minutes of the device being discovered, the road was closed to all traffic until the device, which turned out to be a spent flashbang, was removed.
"A flashbang is a flare which flashes when thrown and Paul must be commended for being alert to the possible danger, even though this time it turned out to be a spent one," he added.
Police are now investigating where the flashbang came from.
The incident occurred on Thursday, September 18.