Four people have been killed and 123 others wounded in an attack carried out by a gunman in the eastern Belgian city of Liege.

Belgian officials say the gunman lobbed hand grenades and fired a rifle at a bus stop in Saint Lambert Square, a busy shopping area in Liege.

Authorities identified the attacker as Nordine Amrani, who has been convicted in the past of drug and illegal arms possession, among other crimes. He was among the four people killed, with witnesses saying he committed suicide.

Authorities have not explained his motive for the attack, but they say he had been summoned for police questioning.

After the attack, police sealed off the area as emergency rescue teams responded to help the victims.

##