Police will "maintain a visible presence" in west Belfast after attacks on two Glider buses on Monday.
Bricks were reportedly thrown at a bus on the Stewartstown Road shortly before 19:00 GMT.
Then, at about 19:55, a member of a group which initially refused to get off the bus, reportedly threw a brick at a window.
Police said it was "sheer luck" no one was injured by the "senseless, reckless and dangerous" behaviour.
"The consequences are huge," said Police Service of Northern Ireland (PSNI) Insp Karen Hamill.
"It's not just the follow-on disruption to members of the public and financial cost of repairs, you are risking the safety, even lives, of those on board, from the driver to children and families.
"Think of the potential consequences of your actions, and stop and consider the impact of getting a criminal record."
A Translink spokesperson condemned the attacks but added that "thankfully this is not a common occurrence".
It briefly withdrew Glider services to the Colin Connect terminus "in the interests of the safety of our staff and passengers" following the incidents, with the buses instead turning at the Michael Ferguson roundabout.
The service to Colin Connect resumed on Tuesday.