Police are investigating after a man was robbed while on a train at Blacktown overnight, NSW Police say.
Just before 12am tomorrow, a 24-year-old man was on a west bound train approaching Blacktown.
Police were told up to eight teens approached the man as he got up to leave the train.
One teen produced a knife and demanded cash and his property, which the man complied.
The teen were last seen running from the train at Blacktown Railway Station.
Police from Blacktown Local Area Command were notified of the incident and patrolled the area without success.
The group of teens is described as being aged in their late teens and were of African, Caucasian, and Pacific Islander / Maori appearance.
Anyone with information is urged to contact Blacktown Police or Crime Stoppers.