A Lebanese-Canadian academic should stand trial in France over the 1980 bombing of a Paris synagogue – three years after magistrates deemed the evidence against him "not convincing enough", a French appeals court ruled. Hassan Diab, 67, is accused of planting a bomb at a synagogue in Paris that killed four and injured 46. It was the first fatal attack on Jews in France since the Nazi occupation in the Second World War and was part of a wave of Palestinian-linked violence in Europe during the 1970s and 1980s. He was extradited from Canada to France in 2014, but released in 2018 after investigating magistrates dismissed the case, saying the evidence was too weak. On Wednesday, a Paris appeals court overturned that decision and ordered him to stand trial in the latest twist in a decades-long legal saga playing out on both sides of the Atlantic. The decision follows a move by French prosecutors to put on trial an alleged associate of Palestinian militant Abu Nidal this year over another decades-old attack. Walid Abu Zayed, 62, will stand trial on charges relating to an attack on a kosher restaurant in 1982 that killed six and injured 22. It was part of a wave of attacks by the Abu Nidal Organisation that included the 1972 Munich Olympics massacre, attacks on airports in Rome and Vienna in 1985 and the assassination of the UAE’s ambassador to France in 1984. Mr Diab's French legal team called the latest ruling crazy and said it was motivated purely by a "politically correct" drive to have a trial at all costs. His Canadian lawyer Donald Bayne called it "the continuation of a long odyssey of injustice ... that flies in the face of the evidence". The decision, he said, was devastating for Mr Diab and his family, who thought they had turned the page. But a lawyer for the synagogue and for the families of two of the victims of the attack hailed the prospect of a trial. "We're almost at the end of a long struggle," Bernard Cahen said. A former professor of sociology at the University of Ottawa, Mr Diab is accused of planting explosives in the saddle bag of a motorbike that exploded outside the synagogue close to the Champs-Elysees, where hundreds had gathered for Sabbath prayers. Investigators blamed the October 3, 1980, attack on the Special Operations branch of the Popular Front for the Liberation of Palestine. Mr Diab always denied involvement, saying he was taking exams in Beirut at the time. He spent nine years either in jail or under strict bail conditions in Canada and France, awaiting trial. After his release from custody in France, he returned to Canada and sued the government there for millions of dollars for extraditing him. Evidence presented against him in France included a sketch of the bomber that resembled him and the discovery of a passport in his name with entry and exit stamps from Spain, where the bomber was thought to have visited. There were also witness statements that claimed Mr Diab was a member of the PFLP. Dismissing the case in 2018, investigating magistrates said the evidence showed that Mr Diab was "probably in Lebanon at the time" of the attack. But the state prosecutor's office continued to push for a trial, saying that while there were doubts as to his whereabouts at the time of the bombing, it was a matter for a court to resolve. During his long battle against extradition, artists and activists in Canada, including filmmaker Atom Egoyan and political activist Naomi Klein, rallied behind him. On Wednesday, Alex Neve, former secretary general at Amnesty International Canada, said Prime Minister Justin Trudeau's government must press France to "drop these unfounded charges against Hassan Diab and not continue with this prosecution". It is uncertain that Mr Diab would be extradited to France again, but his Canadian lawyer Mr Bayne said it was a risk.