Three people, including two police officers, were killed Tuesday morning in a shooting in the Belgian city of Liege, media reports say.

The attack was carried out by a gunman whose motive has not yet been revealed, but local authorities are treating the incident as a terrorist act, according to the BBC.

The shooting began at a cafe near a school. The attacker assaulted police officers with a knife, then used one of their guns to open fire, killing two of them and injuring two others. The assailant went on to shoot a man who was sitting in the passenger seat of a car driving by. The gunman then took a woman hostage at a nearby school before being killed by police.

The attacker had been on temporary release from prison since Monday and is suspected of having been radicalized while in prison, according to Belgian broadcaster RTBF.

Like France, Belgium has been on high alert since the Paris attacks of November 2015, which killed 130 people and involved a Brussels-based cell of Islamic State, and since the 2016 attacks on the Brussels airport and a local subway station, which claimed the lives of 32 people.