Officers from Bedfordshire Police were in Luton town centre yesterday (Sunday) after receiving reports that ammunition had been found in the area.
Officers were searching to recover any outstanding ammunition, but are urging anyone in who finds anything not to touch it and to call police immediately.
An investigation into the circumstances of the incident is ongoing.
Detective Constable Mark Amey said: “Our officers have been in and around the town centre today and our searches have successfully recovered a number of bullets.
“However there may still be some ammunition in the town centre, so it’s really important that anyone who comes across any calls us immediately so we can come and recover it.
“Please don’t touch it, but tell us where it is.”
Anyone who has any information is asked to call 999.
> A 22-year-old man is currently in custody after being arrested on suspicion of possession of a firearm without a certificate.