Vancouver teen thanks Good Samaritan after 'hate motivated' attack.

A Canadian teenager has thanked a commuter who defended her from an alleged racist attacker.

Noor Fadel says she was on a Vancouver train when a stranger approached and began verbally abusing her.

The 18-year-old, who wears a hijab, says the man also threatened to kill her and all Muslims, forced her face towards his crotch and hit her.

A young man stepped up and pushed the alleged attacker away from Ms Fadel.

The Good Samaritan, Vancouver resident Jake Taylor, stood between the two and later accompanied Ms Fadel on to a station platform to await authorities.

Mr Taylor told Vancouver radio station News Talk 980 CKNW that he decided to intervene when he saw the interaction "get really aggressive".

"The moment I saw he put his hands on her I got up, and before I could even get there he had already took a swing and hit her in the face," he said.

He went over, grabbed the man and pushed him towards the train doors.

"There was probably some swearing involved but I won't say it live [on air]," he said.

Ms Fadel said Mr Taylor was "once a stranger now a dear friend who stood up for me no matter for my appearance".

Vancouver transit police also praised Mr Taylor's actions earlier this week.

"We would like to thank and commend the gentleman who intervened in this incident and came to the aid of the woman," they said in a statement.

"He put his own safety at risk and stopped what might have become an even more serious situation."

Ms Fadel sent photos she took of her alleged attacker to police, and they were able to track the man by video to Vancouver International Airport.

A 46-year-old man was later arrested by police for what they describe as an "alleged unprovoked hate motivated attack".

They say the man has no criminal record but is well known to police and has no fixed address.

He was charged with one count of threatening to cause death or bodily harm and one count of assault.

Transit police are also recommending a charge of sexual assault.