A man armed with grenades and an assault rifle opened fire on Christmas shoppers Tuesday in the central square of Liege, Belgium, located east of Brussels.

Four people were killed and dozens of others were wounded. By Tuesday afternoon, the number of those injured rose to 123.

Interior Ministry official Peter Mertens said the attack did not involve terrorism.

Belgian investigators identified the attacker as 33-year-old Norodine Amrani, a Liege resident.

Investigators said Amrani had spent time in jail on charges involving guns, drugs and sexual abuse. It's believed that he was on his way to be questioned by police when he began the attack.

Belgian officials said Amrani walked alone to the busy central square in Liege known as the Place Saint-Lambert. From a platform, he lobbed three hand grenades toward a bus shelter.

Investigators added that he opened fire on pedestrians and still had a number of grenades with him when he died.

Amrani is among the four people who died, but it's unclear if he committed suicide or died by accident.

Two teenage boys and a 75-year-old woman were also killed in the attack.

A 2-year-old girl is among those critically injured, according to reports.

One eyewitness was on his way home from work when he heard gunshots and explosions.

"I heard a loud boom," said witness Dimitri Degryse. "I thought it was something on my car that was broken or something. Then a few seconds after a second boom, and I saw all the glass breaking, I saw people running, screaming."

Police closed off the area, but found no accomplices.