Two men have been taken to hospital – one with a stab wound to his leg and the other with head injuries.
The men, aged 35 and 52, were found injured in Comet Close, New Parks, Leicester at 6.30pm on Monday.
They were taken to Leicester Royal Infirmary.
Two men have been arrested on suspicion of affray and assault.
Police have appealed for witnesses and have searched the area for the knife which was used in the attack.
In a statement, Leicestershire Police said: "Inquiries remain ongoing to establish the exact circumstances surrounding the incident and officers would like to speak to anyone who was in the area and saw what happened."
Contact Leicestershire Police on 101.
