A Canadian journalist has revealed how she helped a teenage girl who was being harassed by a man on a flight.

Joanna Chiu, bureau chief for Star Vancouver, tweeted the entire experience after a man seated behind her asked the teenage girl next to him to show him “dirty photos.”

Chiu said that the man was “obviously delighted to be seated next to a teenager separated from the rest of her family” on the flight with an unnamed Canadian airline.

“He started off by asking about her career plans and laughed when she said she wanted to be CEO and kept giving her ridiculous advice,” Chiu wrote.

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“She was friendly and he seemed to take that as a welcome cue to get very familiar and started teasing her and kept saying that he wanted to take her out to eat, which she was ignoring.”

Chiu then said he “asked for a ‘dirty’ photo while leaning close to her”, which led the journalist to say something to the man, who didn’t respond and went to use the toilet.

She continued: “Another woman seated behind him was listening and monitoring too and while the man was gone she let the teenager know that she had the right to change seats and that she was just behind her if she needed any help.

“I went to get a flight attendant and informed her of what was going on. They checked other witness accounts and the head of the flight service (a woman) asked the man to move.

“He resisted then started swearing at me and asked to talk to the boss and the head flight attendant said ‘I’m the boss, this is really serious and we could land the plane’.

“He moved. The attendants checked in with the young woman and wrote up a report.”

Airline staff later gave Chiu and the other woman cards thanking them for stepping in and helping.

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In a Twitter thread that went to viral, Chui praised the airline for “handling the situation so well” before saying that other adults need to be aware of similar situations.

She wrote: “I’m sure the young woman he targeted will be CEO some day or some other position of influence. She was in the middle of studying when he started harassing her.

“It’s sad these experiences are extremely common. All adults need to be on guard and know there are things we can do to intervene even when a crime hadn’t technically been committed yet.”

Chiu said she also intended to contact the man’s place of employment over the incident.

This article originally appeared on news.com.au.