Police Thursday were investigating a torrent of threatening and racist abuse against a French woman on a Melbourne bus that was caught on camera and went viral on YouTube.
The woman and a group of friends were returning from a day at the beach when one of them began singing in her native tongue, which promoted an angry reaction from some passengers on the packed bus.
One aggressively demanded she "speak English or die" and then threatened to cut her breasts off.
Another man pushing a pram joined in, shouting that he would knife her.
The woman was then told: "Everybody on the bus wants to kill you" before the incident ended with a bus window being smashed.
The woman targeted, Fanny Desaintjores, told The Age newspaper she and her friends were terrified they would be physically assaulted.
"I realise that maybe we shouldn't sing on public transport, but I think that's insane that they reacted like that. We're all adults," she said.
"We could have a conversation and talk gently, instead of all these insults and threats."
In an opinion piece, Fairfax Media said the most disturbing thing was that so few people spoke up in defence of the woman.
"The majority of passengers were silent and impassive, probably wishing they were elsewhere," it said.
"A racist, abusive bigot is like sitting next to the smelliest person on the bus -- you hold your breath and count the stops until you can get off."
Parts of the incident were caught on camera by stand-up comedian Mike Nayna and the footage has been viewed thousands of times on YouTube, with the story picked up by French newspapers.
Melbourne police said they were investigating "verbal threats and racist taunts towards a group of women travelling on a bus".
"The incident was reported to police and detectives are appealing for anyone with information to come forward as there were a number of people on the bus at the time," police said.
Nayna, who describes himself as "brown", says that when he asked the passengers to calm down another man started ranting at him about hating black people.
"He said darkies should be kept at the back of the bus where they belong, before repeatedly yelling 'I hate blacks'," Nayna told reporters.