Two drunken men launched a volley of insults at a group of taxi drivers waiting for fares in Northampton.
The drivers were in Mercers Row when the two offenders approached and became racially offensive.
Police are treating the incident, which happened at 6.50pm on Saturday, (June 10), as a hate crime.
The first man was 6ft with a stocky build and he had square-rimmed black glasses. He was wearing a blue jumper, cargo trousers and tanned work boots which looked to be steel toe-capped. He also had words tattooed on his knuckles.
The second man was white, 6ft with a tanned complexion and white hair. He was wearing a light checked shirt and blue trousers.
A police spokeswoman said: "Both men spoke with Irish accents and may have been drinking, but not to such an extent they did not know what they were saying or doing."
Anyone who recognises these descriptions or has information should call Northamptonshire Police on 101 or Crimestoppers, in confidence, on 0800 555111.