A man was reportedly attacked with the tool outside a Cash Converters in Nuneaton.
On Saturday afternoon police received calls reporting a man in his 40s allegedly being hit over the head with an angle grinder at a shop on Queen's Road.
The victim was taken to hospital with a head wound but later released.
This morning (29th June) Warwickshire police confirmed that two women from Nuneaton, aged 31 and 47, and a 32-year-old man of no fixed abode were arrested on suspicion of assault.
Both women remain in custody. The man was detained on recall to prison.