Teenager assaulted at Melbourne party

Police are hunting a youth who physically and sexually assaulted a 16-year-old girl at a party in Melbourne.

Several uninvited youths attended the party at St Clare's Parish School hall in Thomastown on August 22, Sexual Crime Squad detectives say.

The teenage girl was allegedly physically assaulted by a group of males in a bathroom inside the hall about 8.30pm.

An unknown man approached the same girl about 9.15pm and lured her behind the building where he committed a sexual offence against her, police say.

Detectives have released a FACE image of a youth they believe can assist with inquiries.