Hailo’s London office has been vandalised by disgruntled cabbies as tension around the use of taxi apps, including Uber mounts.
The word "Scabs" was written on the wall outside the Hailo office and police were called to the scene after punches were thrown, according to reports from the BBC.
Black-cab drivers are concerned that the mobile taxi ordering service is undermining their business.
Steve McNamara, head of the London Taxi Drivers' Association said that "feelings were running high".
Speaking about the incident outside the Hailo office he said: "Things turned a little bit nasty, punches were thrown and the police were called."
He added that cab drivers were deleting the app and removing the Hailo stickers from their cars.
Earlier this week cabbies drew ranks around a similar new app Uber, which enables users to search for vehicles near them before booking an agreed fare by credit card. This negates the need to exchange money, stoking accusations that Uber has found a way to skirt industry regulations by positioning itself as a taxi ‘facilitator’ rather than a provider.