A woman has been arrested for allegedly making racist comments to other passengers on a packed tram. The incident was filmed and posted online, prompting police to investigate.

The clip (which contains explicit comments some viewers may find offensive) had been viewed more than 124,000 times by Monday afternoon after being uploaded to YouTube on Sunday, and shows a woman with a child on her lap shouting abuse at passengers. The incident happened on the Croydon to Wimbledon tramlink. British Transport police said a 34-year-old woman had been arrested on suspicion of a racially aggravated public order offence.

The video footage, which sparked a Twitter trend with the hashtag #MyTramExperience on Monday, shows a woman complaining about ethnic minorities living in Britain. She starts by saying: "What has this country come to? … with loads of black people and a load of fucking Polish. You ain't English either. None of you are fucking English. Get back to your own fucking, d'you know what?

"Sort out your own countries. Don't come and do mine. Britain is nothing now. Britain is fuck all."

One of the passengers on the tram asks her to mind her language, saying: "There are little kids on the tram." The woman points to the child on her lap and says "I've got a little kid here."

Several other passengers complain about her use of language and racist comments, but the tirade carries on for more than two minutes.

Police launched an investigation after the video was brought to their attention on YouTube and Twitter. A spokesman said: "At present it is not entirely clear which tram stops the offence took place between and when it occurred.

"As a result, we need anyone who witnessed this incident, or with any information that could assist our investigation, to contact us."