BOMB disposal experts were called out to a report of unexploded ordnance near the A465 Heads of the Valleys Road on Tuesday evening.
A stretch of the road between Resolven and Aberdulais, and Station Road in Tonna, were both closed after the discovery.
Today, Wednesday, South Wales Police confirmed to the Argus that a bomb disposal team was called in to respond to the incident.
It members analysed the item and "established that it was a training smoke grenade", the force said.
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