Four men arrested over two shop robberies in Sheffield have been released under investigation.
The men were quizzed over robberies at Spar in Bocking Lane, Greenhill, at 9.40pm on Monday and another at McColls in Lowedges Road, Lowedges, the night before
Staff were threatened with a knife in both incidents before cash was stolen.
Detectives are linking the raids.
Anyone with information should call South Yorkshire Police on 101.