Police want to find Melbourne station man

A man on a green motorised scooter is being sought by police after he allegedly left a suspicious package at a Melbourne train station, sparking an evacuation and problems for morning commuters.

Victoria Police want to find the man, aged in his 30s, who got off at North Melbourne train station about 6am and left an item on platform one before boarding a train on the Watergardens line.

The item was found just before 8am on Thursday and looked like an "explosive device", police say.

The bomb squad was called and the item was deemed safe about 9.30am.

The man is described as having short dark hair, facial hair, an olive complexion and was wearing a dark broad-brimmed hat, tan pants, a black coat and boots.

He was carrying a red and black backpack and a green helmet, police said.

As the station was evacuated, trains were temporarily halted, causing morning headaches for commuters on five lines.