Brussels (AFP) - Belgian authorities faced questions Friday over how a convict on a terrorism watch list was able to stab a police officer to death, hours after making threats and demanding psychiatric treatment.

Between 2016 and 2018, Belgium faced a wave of deadly jihadist attacks and police unions and politicians were quick to accuse those currently in office of security failures in the latest case.

The accused is alleged to have lent through a car window outside a central railway station, stabbing two officers in their twenties, killing one after slashing his throat and putting the other in hospital Thursday.

Other officers arrived on the scene and shot the suspect who is receiving medical treatment.

Prime Minister Alexander De Croo paid tribute to the slain officer and Interior Minister Annelies Verlinden said she was “heartbroken” by the attack.

But a police union declared the death “one incident too many”, and has called on fellow officers to join a protest on November 28 against what it sees as lax handling of suspected extremists.

Some political leaders, such as Georges-Louis Bouchez, leader of the liberal MR party, called for an investigation into how the suspect had been free to launch his attack.

“How could an individual classified as a terror threat on the OCAM list be left free by a magistrate even though he had said he wanted to attack police? Unacceptable,” he said.

The suspect in Thursday’s fatal stabbing, 32-year-old Brussels-born “Yassine M.”, had previously been jailed for committing a violent robbery, officials told AFP.

- Incoherent remarks -

His behaviour worsened in prison and in 2015 he was placed in a de-radicalisation programme. After his release in 2019, he was placed on Belgium’s official extremist database.

This list, maintained by the Coordination Unit for Threat Analysis (OCAM), includes around 700 “known extremists and terrorists in the country who are subject to priority monitoring”.

On Thursday, the suspect presented himself at a Brussels police station making what the head of the Brussels prosecutor’s office, Tim De Wolf, described as “incoherent remarks”.

“He spoke of hatred against the police and asked to be taken care of psychologically,” De Wolf said.

Yassine M. was taken by officers to the psychiatric emergency room of a Brussels hospital, but was not arrested or detained as he did not meet the criteria for an involuntary committal, the officials said.

Later the same day he left the hospital and encountered two police patrol officers in their car, stopped at a red light near the Gare du Nord railway station in central Brussels.

Investigators told reporters that the suspect shouted “Allahu akbar” – “God is greatest” – as he lunged through the window into the car and stabbed at the patrolmen.

One officer, identified as 29-year-old Thomas M., was wounded in the throat and died shortly afterwards. The second officer, 23-year-old Jason P., underwent surgery for wounds to the right arm.

The officers managed to raise the alarm and a second patrol arriving at the scene shot Yassine M. and arrested him. He is being treated in hospital for bullet wounds.

Vincent Gilles, head of the police union SLFP, demanded to know why the suspect had been allowed to leave the hospital even after making threats.

“The families are entitled to have answers as soon as possible. The political, judicial and medical actors must take a stand and must not remain silent,” he said.

- Islamist attacks -

But officials said that a 1990 law strictly limits who can be held in custody on mental health grounds.

“He was voluntary,” De Wolf said, explaining that police had left the suspect at the hospital under the care of nurses.

“Later, the police contacted the hospital again to check whether the person had been kept under observation. It turned out that he had left the hospital,” the Brussels prosecutor’s office said.

The trial of those accused of involvement in the 2016 Islamic State group attacks that killed 32 people at the city’s main airport and in a crowded metro station is underway in Brussels.

Between 2016 and 2018 Belgium saw several fatal Islamist terror attacks against the police or military.

The last attack classified as a terrorist offence took place in the city of Liege in May 2018, when a radicalised attacker shot dead two policewomen and a student before being gunned down by officers.