On Thursday 18 March officers carried out two warrants at addresses on Kelham Street, Kelham Island, and Preston Street, Sharrow, this morning (29 March).
Two men, aged 19 and 48, were arrested on suspicion of attempted murder and drugs offences.
Two further men, aged 28 and 45, were arrested on suspicion of drugs offences.
Enquiries into the incident, in which an 18-year-old man suffered serious injuries, are continuing.
Police were called to Queens Road, close to Halfords, at 9.50pm on 18 March after reports of a fight taking place.
If you saw what happened, or have any information about the incident, please contact us on 101 quoting incident number 1010 of 18 March or speak to Crimestoppers.