A suspected explosive device was found outside a Turkish community centre in central Brussels on Friday, Belgian prosecutors said.
Police were called after a plastic bag was left in front of the building at around 1.30 pm local time (1230 GMT).
"A suspect package was found in front of the Turkish Federation of Belgium," said Denis Goeman, a spokesman for the prosecutor's office.
A bomb squad was called to the scene and the situation no longer posed a threat to the population, he said.
"All I can say is that the device was potentially explosive," Goeman said, adding that the investigation was still under way.
The event took place in the Brussels district of Schaerbeek, which has a significant Turkish population.
Belgian media said a gas cannister and fuse mechanism were discovered inside a plastic bag.
Residents, who had been evacuated, were allowed back to their homes late in the afternoon, but the traffic was blocked.