The main suspect in the trial of nine alleged jihadists accused of taking part in the March 2016 bombings in Brussels denied on Wednesday having any knowledge of the plot.

Salah Abdeslam, a 33-year-old Frenchman already jailed over his role in the Paris terror attacks of November 2015, was facing his first day of cross-examination in the Brussels trial.

On March 22, 2016, two suicide bombers blew themselves up at the Belgian capital's airport and another one targeted a metro station, killing 32 people and wounding many more.

Investigators believe the Islamic State group cell behind the attacks was linked to the group that carried out the Paris attacks, which left 130 dead.

Abdeslam has been sentenced to life in prison without parole for his role in the French massacre, but on Wednesday he insisted that he had no knowledge of the Belgian plot.

"My presence in the dock is unjustified," he told the court. "This is not justice, this is trying to make an example of someone."

Abdeslam argued that he could not have taken part in planning the Brussels attacks because, he claimed, they had been planned in the four days between his March 18 arrest and the fatal blasts.

"I was not aware of anything," he said.

The trial began on December 5 last year, in a specially built high-security courtroom in the disused former headquarters of the NATO military alliance.

Wednesday was the first day of questions for the defendants.

- 'Too many sins' -
 

Abdeslam's childhood friend and fellow accused, 38-year-old Mohamed Abrini, also downplayed his role, even though he is accused of being the only surviving member of the attack team.

Abrini has been identified by prosecutors as the so-called "man in the hat" seen on airport surveillance footage, apparently changing his mind at the last minute and deciding not to detonate his bomb.

Two more attackers, Najim Laachraoui and Ibrahim El Bakraoui, went through with their suicide bombings, and a third, Khalid El Bakraoui, attacked the Maalbeek metro station.

Abrini told the court: "They're trying to pin this all on us. Just like in Paris, they'll convict for what others did."

Abrini left Paris on the eve of the attacks, but the French court concluded that he had planned to carry out a suicide bombing there before another last-minute change of heart

He was given a life sentence, with no chance of parole before 22 years served, but did not lodge an appeal.

"After 10 months on trial, we were at the end of our tether. Even if I had been sentenced to death I would not have appealed," he told the Belgian court.

Wearing an orange hooded T-shirt under a dark jacket, with close-cropped hair and a full beard, Abrini argued that the defendants appearing in Belgium were "not the tip of the pyramid".

"You never caught those pulling the strings, but you have to trot out someone, and that someone is us," he said, accusing the prosecution of pandering to a public thirst for revenge.

The defendant's version of the events in the run-up to and day of the attacks will be examined later in the trial, but on Wednesday they were cross-examined about their character and motivations.

Asked by the presiding judge Laurence Massart to describe his qualities, Abdeslam said: "I've always tried to do good. It's what I've always done throughout my life."

"And your faults?" the judge continued. Abdeslam paused for a moment to reflect, then replied: "I don't know of any."

Faced with the same question, Abrini responded that his belief in God was a strength but that he has "millions of faults -- I commit too many sins".

The trial continues.