Five STIB inspectors were targeted with fireworks and firecrackers on Tuesday afternoon in the Brussels district of Neder-over-Heembeek, according to the public transport company.
The incident occurred around 17:15 at the Beyseghem stop in the Versailles neighbourhood.
A ticket inspection operation had been set up in collaboration with Brussels police, following stone-throwing attacks on STIB buses in early November in the same area.
"Our inspectors were waiting in their vehicle for the arrival of the police," said STIB spokesperson Guy Sablon.
"As they got out, before the police arrived, they were suddenly targeted by fireworks. The police arrived shortly after and searched the area but could not apprehend any suspects," he said. "Our agents were taken to hospital. Although none sustained physical injuries, one is experiencing ear pain, likely due to auditory damage."
All the affected STIB inspectors are on sick leave for at least several days.
The Brussels police confirmed they conducted searches in the area following the incident but have yet to identify any suspects. The investigation is ongoing.
