Police in Belgium have discovered a woman\'s body at the home of a gunman who went on the rampage in the city of Liege, killing four people and himself. The body was found in a shed at Nordine Amrani\'s property, a justice official told Belgian radio. Amrani launched his attack with guns and hand grenades in a busy marketplace in Liege on Tuesday, causing panic among Christmas shoppers. Nearly 125 people were wounded, some critically. Belgian media reports say the body found at the killer\'s property was that of a 45 year-old cleaner, who worked for one of Amrani\'s neighbours. \"It was found in a shed which he used, notably to grow cannabis,\" Liege\'s prosecutor general, Cedric Visart de Bocarme, told Belgian public radio, RTBF. The authorities are trying to determine what motivated Mr Amrani to go on his killing spree. Police have said he was known to them for previous drugs and firearms offences and acted alone in the attack. Prime Minister Elio Di Rupo said it had been \"an isolated case\". The city is to hold a minute\'s silence and a vigil at midday on Wednesday, the AFP news agency reports. A 17-month-old girl became the fourth victim late on Tuesday, dying in hospital despite undergoing hours of emergency treatment. Belgium\'s Home Affairs Minister Joelle Milquet said four people remained in a critical condition. The BBC\'s Matthew Price, in Liege, says the central Place Saint-Lambert, where the attack took place, has been re-opened to the public, but blood stains, shattered glass and bullet marks remain. Officials have ruled out organised political terrorism or a known mental illness as Amrani\'s motives but have yet to determine why he opened fire They will now need to examine whether there was anything to indicate in advance that he might have posed a danger to the public, says our correspondent. Amrani, a resident of Liege, had been jailed for 58 months in September 2008 for possessing firearms and drugs, media reports said. Officials did not confirm this, but said they were aware he had spent some time in prison. \"At no moment in any of the judicial proceedings against him was there a sign of unbalance,\" Daniele Reynders, the public prosecutor for Liege, told reporters. Amrani is reported to have been on parole and on Tuesday, had been asked to attend a police station for an interview in connection with charges against him. Instead, he took an assault rifle, revolver and hand grenades into the busy town centre square, close to the courthouse. At around midday, he threw three grenades at people waiting for buses then opened fire, sending hundreds of people fleeing in panic. \"He wanted to hurt as many people as possible,\" journalist Nicolas Gilenne told AFP. \"I heard four explosions and shots during about 10 seconds.\" A 15-year-old boy died instantly, while a 17-year-old boy and a 75-year-old woman died later in hospital. One official told AFP that a Christmas market was meant to be taking place in the square that day but its opening had been postponed because of bad weather. \"Otherwise many more would have died,\" said the official. Amrani died at the scene, but officials said he had not been shot by police. Some witnesses said he had shot himself in the head. Mr di Rupo, who has only been in office since last week, said there were \"no words to describe this tragedy\". \"The whole country shares the pain of the families affected. We share the shock of the population,\" he said as he visited the square. But he said: \"This is an isolated case. This is not about terrorism.\" Belgium\'s King Albert and Queen Paola II also visited Place Saint-Lambert on Tuesday evening to pay their respects. Liege\'s mayor Willy Demeyer, said the attack had \"sown sorrow in the heart of the city\".