Neither cited incident identifies a contractor killed in a motorcycle crash involving a tree.
Police recovered a shotgun from a pond in Singarpur of Fatepur Union, Araihazar, at about 8am on 3 August.
Araihazar police said fishermen found the weapon while casting a net to catch fish, after which local residents alerted the police.
The officer responsible for arms maintenance at Araihazar police station said the weapon's butt number, 651, matched the station's arms register.
Police said it was among weapons looted from the station during the 2024 student-public movement and that investigators were examining how it reached the pond and how long it had been there.
Separately, a bus lost control on the slope of the Golapbag flyover in Jatrabari on the afternoon of 3 August, striking an autorickshaw and pedestrians before mounting the footpath.
Jatrabari police said one person was killed and two people were injured in the crash.
Police identified the deceased as Abdullah Al Mamun, 30, and said his body was kept at the Dhaka Medical College Hospital morgue for a post-mortem examination.
Police identified the injured as autorickshaw driver Mozammel Haque, 55, and pedestrian Abu Kalam, 50, and said they were being treated at Dhaka Medical College Hospital.