This is the moment shocked tourists were caught in the middle of a foul-mouthed row between teenage girls and another London Underground passenger over an empty seat.

The incident, which took place late at night on the Piccadilly Line, was filmed and posted online by American tourist Zainab Hameed.

The fracas seemed innocuous at the start, after one of the teenage girls stopped another passenger from sitting in a spare seat.

But it escalated quickly, with one man having to be restrained by a friend as the carriage was filled with shouting and swearing.

Ms Hameed, 22, from Los Angeles, was stunned at how quickly the dispute turned into a full blown argument.

The incident, which took place late at night on the Piccadilly Line, was filmed and posted online by American tourist Zainab Hameed

Ms Hameed said the 'ferocious' exchange went on for 20 minutes after she filmed the clip

The man was held back by the woman he was travelling with, as his argument with the girls became heated

She said she was with her younger brother and had boarded at Leicester Square.

Three teenage girls also boarded the carriage - two sat down and the other went to stand at the back as there were no seats left.

At the next stop younger boys got on the train and a seat became free. However, one of the girls stopped one of the young boys from sitting down.

As the row escalated, the girls take offence at the older passenger and one says: 'You did not just say that seriously? Just who the f*** do you think you are?'

She is met with angry comments from a man and woman of 'Just grow the f*** up' and 'This has nothing to do with the fact you’re 17 years old, it is to do with the fact you are f***** rude'.

The 17-year-old's actions did not go down well with other Underground passengers and one man confronted her, which sparked the argument.

Ms Hameed said the 'ferocious' exchange went on for 20 minutes after she filmed the clip.

She told the Daily Mirror: 'You get bad people everywhere, but it was pretty scary.

'I just couldn't believe they were just 17 years old, they were really rude.

'My brother was sat right next to the girl and he was scared. It just escalated really quickly.'

The 17-year-old's actions did not go down well with other Underground passengers and one man confronted her, which sparked the argument