One policeman has been shot dead and two others wounded in central Paris, French police say, with their suspected attacker killed by security forces.
A lone gunman opened fire before being killed as he fled the scene, police say. The Champs-Elysees was sealed off.
President Francois Hollande said that he was convinced the attack was “terrorist-related”.
So-called Islamic State (IS) said that one of its “fighters” had carried out the attack.
Several candidates in Sunday’s presidential election have ended their campaigns early as a mark of respect, with the centre-right’s François Fillon calling on others to halt theirs too.
“On the face of it, the officers were deliberately targeted,” interior ministry spokesman Pierre-Henry Brandet said.
Because of its worldwide renown and its large number of visitors, the Champs-Elysees has long been seen as a potential target, the BBC’s Hugh Schofield reports from the French capital.
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