Police arrest 16-year-old, 17-year-old and 18-year-old over ‘savage’ attack on 22-year-old man

• Follow our Australia news live blog for latest updates

• Get our breaking news email, free app or daily news podcast

Three teenagers have been charged with murder after a man who tried to intervene and help a 14-year-old schoolboy was killed in a “savage” stabbing attack.

Emergency crews were called to the Mernda train station in Melbourne’s north-east on Friday evening after reports of a fight among teenagers.