Four teens have been arrested after a young man was killed in a brawl outside a Melbourne train station.

A good Samaritan who tried to break up a brawl between teenagers has died in a "savage" edged-weapon attack after four teens set their sights on him.

A good Samaritan who tried to break up a brawl between teenagers has died in a "savage" edged-weapon attack after four teens set their sights on him.

One person is dead after a fight broke out near Mernda railway station in Melbourne’s north-east, police say.

One person is dead after a fight broke out near Mernda railway station in Melbourne’s north-east, police say.

A security guard who tried to stop a robbery has been stabbed to death at a Melbourne station, with four teenagers arrested.

A security guard who tried to stop a robbery has been stabbed to death at a Melbourne station, with four teenagers arrested.

Roads have been blocked and 13 people arrested at gunpoint, after tactical police swarmed a home in Melbourne's west.

Roads have been blocked and 13 people arrested at gunpoint, after tactical police swarmed a home in Melbourne's west.

Roads have been blocked and 13 people arrested at gunpoint, after tactical police swarmed a home in Melbourne's west.