A man in his 20s was taken to hospital for treatment for puncture/stab wounds to his leg and abdomen after reports of a number of people fighting in Boston.
Police were called to an altercation in Tunnard Street in the town at around 11pm on July 14 and officers arrested two men and one woman, all in their 20s.
They have since been released under investigation.
The victim’s injuries were not serious or life threatening, police said.
Lincolnshire Police are appealing for witnesses who have not yet come forward and anyone with information should contact police on 101 quoting incident number 549 of July 14.