A man armed with grenades and an assault rifle attacked holiday shoppers Tuesday at a central square in the Belgian city of Liege. Five people died, including the attacker, and 122 others were wounded, officials said.

It was not immediately clear what motivated the attack in the busy Place Saint-Lambert square, the central entry point to downtown shopping streets in the city in eastern Belgium. The attack prompted hundreds of shoppers to stampede down old city streets, fleeing explosions and bullets.

Interior Ministry official Peter Mertens said the attack did not involve terrorism but did not explain why he thought that.

Belgian officials identified the attacker as Nordine Amrani, 33, a Liege resident who they said had done jail time for offences involving guns, drugs and sexual abuse. He was among the dead, but Liege Prosecutor Danielle Reynders told reporters it was unclear if he committed suicide or died by accident. He did not die at the hands of police, she said.

The other dead were two teenage boy students aged 15 and 17 and a 75-year-old woman, while an 18-month-old toddler died Tuesday evening in the hospital, Liege police said.

Reynders said Amrani had been summoned for police questioning on Tuesday but the reason for the questioning was not clear. He still had a number of grenades with him when he died, she said.

Officials said Amrani left his home in Liege with a backpack, armed with hand grenades, a revolver and an FAL assault rifle. He walked alone to the central square, then got onto a platform that gave him an ideal view of the square below, which was bedecked with a huge Christmas tree and crowded with shoppers.

A policeman stands guard in fron of a ferris wheel in Liege, Belgium, after a man armed with grenades and an assault rifle attacked holiday shoppers at a central square. (Timur Emek/Dapd/Associated Press)

From there, Amrani lobbed three hand grenades toward a nearby bus shelter, which serves 1,800 buses a day, then opened fire on the crowd. The explosions sent glass from the bus shelter across a wide area.

Marian Todorov, a Bulgarian student who is studying international management in Liege through an exchange program, says he was in the gym about 100 metres away from the square when he heard gunshots.

"After hearing the shots everybody started running and there was panic everywhere," he told CBC News in an email. "People started running and screaming."

At first, police suspected there was more than one attacker, Todorov said. Officers blocked the area around the buildings and told people to stay inside.

"During the attack I didn't really understand what was going on, due to lack of information. The sight of all the people running and shouting definitely scared me," Todorov said. "The shock came afterwards when I saw the number of ambulances that were coming and going from the scene of the accident."

Canadian student heard gunshots

Canadian Kiersten Ermelbauer, a 21-year-old student from the University of Lethbridge on a one-semester exchange in Liege, said she lived just 10 minutes away from the square. At around 12:30 p.m. local time, she says she heard gunshots. Ermelbauer, originally from Calgary, stayed inside after that, but she could still hear the chaos on the street.

Police and rescuers stand downtown Liege, Belgium, following the attack. (Timur Emek/Dapd/Associated Press)

"You just heard helicopters and sirens for hours," she told CBC News in a phone interview.

Jacqueline Burt, another Canadian student from the University of Lethbridge, said after word of the attacks the phone networks were tied up with people trying to reach their loved ones.

"It was just mass confusion. So many rumours," she said. "[At one point] I heard there were three gunmen."

Burt said the University of Lethbridge sent out email alerts looking for confirmation from the students.

Ermelbauer said all four students from the university were accounted for.

The attacks left Burt unsettled, not just because they were close to home, but because she regularly walked through the central square.

"Yesterday, at the same time, I was there," she told CBC News in a phone interview. "If it was just one day earlier … It has quite an impact, especially when you're far away from home."

As soon as the shooting began, hundreds of people fled the square as well as a Christmas market in an adjacent square, rampaging through old city streets looking for cover. Video from the scene showed people, including a large group of children, fleeing the city centre, some still carrying shopping bags.

As police hunted for possible accomplices, residents were ordered to stay in their homes or seek shelter in shops or public buildings. As sirens howled and a police chopper roared overhead, a medical post was set up in the nearby courtyard of the Prince Bishops courthouse. Dozens of emergency vehicles took victims away for treatment.

Police closed off the area but found no accomplices and calm returned a few hours after.

The Place Saint-Lambert and the nearby Place du Marche host Liege's annual Christmas market, which consists of 200 tiny shops and attracts some 1.5 million visitors a year. By dusk, with the Christmas lights gleaming again, King Albert II and Queen Paola came to pay their respects, as did Prime Minister Elio Di Rupo.

Herman Van Rompuy, a former Belgian prime minister who is now president of the European Council, said he was badly shaken by the attack.

"There is no explanation whatsoever," Van Rompuy said. "It leaves me perplexed and shocked."

View Larger Map With files from CBC News