LIEGE, Belgium - A man 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 were wounded, officials said.

It was not immediately clear what motivated the attack in the busy Place Saint-Lambert, 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 he 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 offenses involving guns, drugs, and sexual abuse. He was among the dead, but Liege prosecutor Danielle Reynders said it was unclear if he committed suicide or died by accident.

The other dead were two teenage boys, age 15 and 17; a 75-year-old woman; and an 18-month-old toddler, police said.

Local news media described Amrani as a weapons expert, skilled at repairing firearms, who was sentenced for having 9,500 weapons parts and a dozen complete weapons, as well as for growing 2,800 marijuana plants.

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

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.

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

"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."

"It was total panic, and people were running everywhere," said Catherine Leburton, 55.

As soon as the shooting began, hundreds fled the square. Video from the scene showed people, including a large group of children, running to take cover. 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 helicopter roared overhead, a medical post was set up in a 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 later.

Place Saint-Lambert and the nearby Place du Marche host Liege's annual Christmas market, which consists of 200 tiny shops and attracts 1.5 million visitors a year. At dusk, 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 president of the European Council, said he was badly shaken by the attack. "There is no explanation whatsoever," he said.

Liege is the country's third-largest city, after Brussels and Antwerp.