Four teenage girls were arrested after a couple travelling on a tram with their baby were allegedly racially abused.
The alleged incident took place on the Metrolink service between Rochdale and Oldham.
A video of the altercation, which happened on June 12, has been viewed more than one million times since being posted on Facebook.
A group of about six girls are said to have got on the tram at the Shaw and Crompton station before the incident unfolded.
They are alleged to have made comments about the woman’s head covering.
It is alleged when her husband intervened they became verbally abusive.
In a statement Greater Manchester Police said: “Police investigating the racial abuse of a man and woman on a tram have made a number of arrests.
“At around 3.30pm on Friday June 12, the two victims and their young child were travelling on the Metrolink between Shaw and Manchester when they were racially abused by a group of teenage girls.
“Following enquiries by officers, 4 girls aged between 16 and 18 have been arrested on suspicion of a racially aggravated public order offence.
Further enquiries are ongoing in an effort to identify and arrest the other offenders.”