Glider service routes to Colin Connect in west Belfast have been withdrawn after two separate attacks, union Unite has said.
The vehicles were left with smashed windows after coming under attack from youths.
The Glider will now turn at the Michael Ferguson roundabout and not travel to the Colin Connect terminus, where the attacks occurred.
An urgent meeting is set to take place on Tuesday between Translink, Unite, the PSNI and community representatives.
Chair of the Metro and Gliders’ drivers’ Unite union branch, Michael Dornan said that the two incidents occurred at Lagmore on Monday and involved "a large number of youths".
"In the first incident, a window was broken but thankfully did not give way - saving a young female passenger from what would have been a very serious injury. Nonetheless the girl was left in a state of shock," Mr Dornan explained.
“In a second attack a group of approximately seventy youths had to be put off for not paying – they then viciously attacked the Glider and broke windows."
He said that the attacks were only the latest "in a series of attacks on Glider services".
"Members of our union, who inspect tickets have been subjected to routine abuse for months now – many report being consistently spat at and attacked verbally by youths in anti-social behaviour incidents throughout the West Belfast route.
“Now the drivers are feeling the same pressure. The workers are getting no protection from the company – there are no support cars."
Mr Dornan said if the situation did not improve the service could be withdrawn from the entire west Belfast route.
“Our union fought hard to secure the Glider service and then we had to fight to protect the routes. We believe passionately in public transport and we are rightfully proud of the Glider service but we have to put first the safety and security of drivers, Custom Revenue Protection Officers (CPROs) and the travelling public," he said.
"We know that the people of the area – our customers – will suffer but we have been left with no choice."
Unite Regional Coordinating Officer for workers in Translink, Davy Thompson said the attacks threatened the lives of staff and the general public.
“We recognise that, unfortunately, this decision will result in huge disruption and suffering for the local community who use the Glider service but these attacks threaten life and limb, the responsibility for this outcome lies entirely at the feet of those who attacked the vehicles," he said.
“Unite will be seeking urgent meetings tomorrow with local community representatives, the PSNI and management to seek assurances that these attacks will stop. If they do not, the withdrawal is likely to become a suspension – with the same approach taken as with attacks on Metro services."