Montreal police arrested a suspect in a double-murder that took place this week -- then realized they had the wrong man.

The tactical squad surrounded a house at Maurice Duplessis and Rodolphe Forget Blvds. on Wednesday evening, then moved in and arrested a 25-year-old man.

He was taken to a police detention centre for eventual interrogation, which is when police realized the person under arrest was not a suspect in the deadly assault.

He was released without charges on Thursday morning.  

On Saturday night four men were badly hurt in a brawl at St. Laurent Blvd. and Guilbault St. Two men survived gunshot wounds, but two men who were stabbed died of their injuries.

Police have not released the names of the victims, and have only said they were all between 20 and 30 years old.