Lebanese-Canadian national, Hassan Diab, was convicted in absentia of terror charges and sentenced to life in prison for the attack - one of the longest unsolved crimes in France.

A court in Paris has issued an arrest warrant for Diab, who lives in the Canadian capital, Ottowa.

He denies wrongdoing and claims he was in Lebanon at the time of the atrocity, insisting he is a victim of mistaken identity.

French authorities accuse Diab of planting a bomb outside the synagogue where 320 worshippers had gathered to mark the end of a Jewish holiday on the evening of 3 October 1980, including children celebrating their bar mitzvahs.

Investigators initially suspected far-right extremists before shifting their focus to Palestinian militants.

The attack was attributed to the Popular Front for the Liberation of Palestine-Special Operations however no one ever claimed responsibility.

Many were surprised by the conviction on Friday - with a magistrate who investigated the case testifying for the defence that there was not enough evidence to convict Diab.

The head of France's leading Jewish group, CRIF, welcomed the outcome - and called on authorities in Canada to arrest Diab.

A lawyer representing the victims said the trial would serve as a deterrent against other terrorist and antisemitic acts.

Canada authorised Diab's extradition to France in 2014 as part of an investigation.

But after three years in pre-trial detention, anti-terrorism judges ordered he should be freed due to a lack of evidence.

An appeals court later ruled he should face trial on terror charges, with the hearing beginning earlier this month, however Diab remained in Canada throughout.

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Haunted by ordeal

Survivors spoke publicly about their ordeal, describing years of physical and mental anguish.

Some laid bare their grief for lost children or siblings, while others revealed how they were haunted by the sound of motorcycles after the attack.

Diab's lawyer, William Bourdon, urged the court to acquit the defendant, saying a conviction would be a "judicial mistake" - while Amnesty International called the case "flawed and baseless", arguing that it "undermines effective justice for victims".

Some lawyers for the 18 people and six groups involved in the case conceded it was hard to build up a case after more than 30 years - in particular without DNA evidence or mobile phone data used in current investigations.