One man was seriously injured following a brawl at a basketball match, about 8.30pm on Sunday, at a sporting venue in Altona North.

A fight broke out between a group of men and the organisers of the match.

A Werribee man, 22, suffered stab wounds to his upper body and was taken to hospital with non life-threatening injuries.

Another 22-year-old man was treated at the scene by paramedics.

"Investigators believe a number of people were at the venue at the time of the incident and are keen to speak to any witnesses," police said.

It followed another stabbing on the other side of town at Westfield Doncaster just before 6pm on Sunday.

A fight broke out between two people, a 17-year-old Box Hill boy and a 20-year-old Mooroolbark man and a group of five to six youths.

Police believe the fight started when one of the youths tried to steal a hat and mobile phone from the 17-year-old.

As a result of the fight a 17-year-old Ivanhoe boy was rushed to hospital with serious injuries after he was stabbed, another was arrested and taken to hospital as a precaution after being struck to the head during the brawl.

Police are still trying to identify all involved in the incident.

Australian Associated Press