LIEGE/BRUSSELS • Belgian authorities faced questions yesterday over why a prison inmate, suspected of links to radical Islamists in jail, was let out for a day, enabling him to carry out what police called a "terrorist attack" in the city of Liege.

The justice minister, who oversees the prison service, said he felt "responsible" for Tuesday's bloodshed in which two policewomen and a bystander were killed. The attacker was shot dead by police at a nearby school shortly afterwards.

"The question of whether this man should have been given leave is striking because he killed three completely innocent people with a wish to kill himself," Mr Koen Geens told RTBF radio.

Interior Minister Jan Jambon said authorities were still examining the motives of Benjamin Herman, a 31-year-old Belgian drug dealer who had been in jail for years but was let out for a day on Monday to prepare for an eventual release in 2020.

Mr Jambon confirmed to RTL radio that Herman was also believed to have killed an acquaintance 50km away on Monday night.

"It could have been because he had nothing to look forward to, because he also killed someone the night before, the guy's psychology and the fact, it seems, he may have been on drugs."

But federal prosecutors said there was evidence that they were dealing with "terrorist murder". Herman had shouted "Allahu Akbar", the Muslim affirmation of faith, during his attack and he had had contact with Islamist radicals in jail in 2016 and early 2017.

He also appeared to have followed online exhortations from the Islamic State in Iraq and Syria militant group to stab police officers and use their service weapons to shoot others, prosecutors said.

"Everyone in Belgium is asking the same question: how is it possible that someone convicted of such serious acts was allowed to leave prison?" Deputy Prime Minister Alexander de Croo was quoted as saying.

REUTERS