Two police officers and one other person were killed during a shootout with an armed assailant in the Belgian city of Liege on Tuesday, authorities said. Officials are investigating the attack as a terrorist incident.

In a press conference, Belgian prosecutors said that two police offers were attacked from behind by the assailant, who was armed with a knife. He took one of their guns and used it to kill them, then fled the scene. The assailant then shot and killed a 22-year-old passenger in a parked car and took a woman hostage at a nearby school before being killed by police, according to reports.

In a statement on Facebook, local police said two other police officers were injured.

Belgian prosecutors in charge of terrorism took over the investigation Tuesday.

"There are elements that point in the direction that this is a terrorist act," Eric Van Der Sypt, spokesman for the Belgian federal prosecutors office, said.

The situation around the shooting was, however, deemed fully safe and a crisis center official in Belgium told the Associated Press new agency that there was no reason to increase the country's terror threat level.

Video posted on social media appeared to show people running, and approximately six gunshots could be heard.

The police and military in Belgium have been on alert since 32 people were killed in a 2016 suicide bomb attack on the Brussels airport and subway system.