A man is being sought by police for directing "horrific" anti-Semitic abuse towards Jewish children on the London Underground.
He was filmed reading Bible passages to two boys in skullcaps travelling with family on the Northern Line at about midday on Friday.
"He was just screaming at these children," said Chris Atkins, who filmed the incident.
British Transport Police is looking for the man and appealing for witnesses.
Mr Atkins recorded the altercation for about two minutes "on instinct" before moving to swap seats with the young boy next to the man.
"It was the children that really got me and everyone else, he was just screaming at these children. It was horrific in every sense," he said.
"He... said in the Bible [that] Jews killed Jesus and they are all slave masters. I've lived in London for 20 years and you're used to people ranting on the Tube - it was only after a minute I realised, 'hang on this is really, really anti-Semitic'."
The man was seen in the video threatening a man off-camera after he tried to intervene. A woman in a hijab also confronted him.
"The Muslim woman... really, really took him to task, very firmly and persistently," Mr Atkins said.
"In this day and age we are told how intolerant everyone is and all religions hate each other and there you had a Muslim woman sticking up for some Jewish children."
Mr Atkins said the family got off the train a few stops later at Leicester Square and the father of the two boys gave him consent to share the video on Twitter.
British Transport Police said: "A video circulating online showed passengers being harassed and being targeted with anti-Semitic abuse.
"Anyone who knows the identity of the man in the image is asked to contact BTP."