Police are hunting offenders in Victoria and NSW for allegedly masturbating in public spaces and engaging in "lewd" acts. It's alleged some of the men directed their actions at underage girls on public transport. Police are asking for anyone with information about these men to contact Crime Stoppers. Victoria's Transit Crime detectives are calling for help to identify a man who allegedly performed a "lewd act" on a bus in Glen Waverley in April. Police said the man allegedly began masturbating at about 11.05am on Friday April 21 when he boarded a bus at Glen Waverley Railway Station. The act was allegedly directed at a 17-year-old girl. Police believe the man they're seeking got off the 753 bus at Jells and Ferntree Gully roads. He's described as medium build with a bald head and short grey hair on the sides. He may also be using a crutch or walking stick. The man was last seen wearing a black coat and blue jeans with a grey shopping trolley and a green bag, police said. IN OTHER NEWS: NSW Police are asking for public assistance to find a man that was involved in an alleged sexual act at a South Coast railway station on April 24 at 11.40am. A man tried to board a Kiama train, bound for Bomaderry, while masturbating, police said. Staff removed the man from the train and the station after passengers raised the alarm about his behaviour. The man is described as aged in his late 20s or early 30s with a medium build and dark hair. He was wearing a black hooded Everlast jumper and long black pants, police said. Victoria's Transit Crime detectives are seeking public assistance for an incident in Hampton, a suburb in Melbourne's south east. A man allegedly began masturbating on a bus at about 3.50pm on Tuesday, 3 April. Police were told the sexual activity was directed at a 16-year-old girl. The man is described as having a solid build, short brown hair and brown eyes. He was last seen wearing a cream and grey jacket with dark buttons, cream knee length shorts and was carrying a black backpack. Police believe the man boarded the bus at Hampton station and got off at the Centre Dandenong Road and Dingley Village Shopping Centre stop. Anyone who recognises the men or has information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au Support is available for those who may be distressed.