A man who was being questioned over the stabbing of two teenagers in Melbourne's west has been released without charge.

A 19-year-old was arrested yesterday but released pending further investigations.

A 16-year-old boy was stabbed in the stomach and wrist after a fight with a group outside a house in the inner-Melbourne suburb of Footscray shortly after 10:30pm (AEDT) on Saturday.

Officers were called to a nearby fast food restaurant just minutes later, and found a 15-year-old boy suffering from multiple stab wounds.

He is being treated in the Royal Children's Hospital for serious but non life-threatening injuries.

Police believe the a group of offenders was involved in both attacks, and have appealed for witnesses to come forward.

Anyone with any information is urged to contact Crime Stoppers on 1800 333 000.