Translink has said it will enforce a "zero-tolerence" approach to ensuring staff and passenger safety following incidents on its Glider bus service in west Belfast.
The warning comes as two inspectors were assaulted in separate incidents on Wednesday, with one treated in hospital for injuries.
The first incident happened at around 8:50am on board a Glider in the Beechview Park area.
A man described as being in his mid-twenties, with ginger hair and wearing a grey hooded top and dark coloured bottoms, was reported to have assaulted the male inspector before exiting the vehicle. The victim was treated in hospital following the incident.
Later, at around 5pm, it was reported that a male inspector was assaulted at a Glider stop close to Falls Park.
Police have urged witnesses or anyone with information on both incidents to contact them on the non-emergency 101 number.
Meanwhile, a woman has been charged by police following an incident involving an inspector in the Glengoland Avenue area of Dunmurry on Monday.
The 44-year-old has been charged with assault occasioning actual bodily harm, assault on police, disorderly behaviour, and possession of an offensive weapon in a public place.
She is due to appear before Belfast Magistrates Court on May 30, and charges will be reviewed by the Public Prosecution Service.
Translink's Belfast area bus services manager Damian Bannon said: “The safety of our customers, staff and the wider public is our top priority at all times and the vast majority of our passengers experience safe and comfortable journeys.
“Translink and our unions, GMB and Unite, strongly condemn these incidents on our staff, which have all been reported to the PSNI and which have led to arrests in one case so far.
“We have zero-tolerance towards all anti-social behaviour. We take a multi-agency approach to mitigate this behaviour, working closely with the PSNI, including Neighbourhood Policing Teams and the PSNI Safe Transport Team, as well as community and elected representatives to reduce and prevent anti-social behaviour. Positive engagement is also continuing with our trade unions.
He added: “We have a range of measures in place to enhance safety including CCTV systems on board our Glider vehicles and at halts; and our staff use body-worn cameras.
“We also offer a reward of up to £1,000 for anyone prepared to give evidence which leads to a conviction.”