Investigators found a cache of weapons at the home of the 31-year-old man who rammed his auto into a police van on the Champs Elysees avenue on Monday, a judicial source close to the investigation said.
The Paris prosecutor's office said Tuesday that the four were detained overnight in the anti-terrorism investigation into Monday's attack.
Dzaziri was carrying in his auto an assault rifle, two handguns, ammo and two large gas canisters, two police sources and the judicial official told the paper.
The interior minister said he would be introducing a bill on Wednesday at a cabinet meeting to extend the state of emergency from 15 July, when it is set to expire, until 1 November.
Police reportedly had to smash the auto windows to pull the driver out and take him into custody.More news: Thousands march against Vladimir Putin as rival Alexei Navalnyis arrested
However, several more attacks have occurred since, with the bloodiest on Bastille Day past year in Nice where a man drove his truck into a crowd, killing 86 people.
"Once again, French security forces were targeted with this attempted attack on the Champs-Elysees", Collomb said, adding that "a number of weapons, explosives to blow up this car" were discovered at the scene.
Police did not fire a single shot at the scene, but officials confirmed that the driver, who had been flagged for extremism, was badly burned and died. The Paris prosecutor's office has opened an anti-terror probe after inspectors found weapons and explosives inside the auto, although the motive is being investigated.
Gerard Collomb, France's interior minister, addressed reporters Monday afternoon, saying that the Champs-Elysees attacker's auto contained weapons and explosives.
The attack Monday was the latest of a string in France and Britain. The attack was carried out by Adam Dzaziri, a man who had been on France's security watchlist since 2015 over ties to "the radical Islamist movement", sources close to the probe said.
- Last month, a man attacked an officer with a hammer at Notre-Dame Cathedral in Paris, proclaiming, "This is for Syria", Collomb said.More news: Tropical Storm Cindy: Street flooding likely Wednesday in New Orleans
"The vehicle contained weapons, explosives, enough to allow him to blow up this auto", Collomb said.
A auto packed with weapons and explosives has rammed a police van on the Champs-Elysees in Paris.
A senior police officer and his female companion were both killed by a radicalised man at their home in the Paris suburbs a year ago.
"By God's grace, we were able to protect him from harm", Mahmoud said.
Police have closed two of the Metro stations on the Champs-Elysees, a world-renowned avenue lined with shops and cinemas that is a major tourist draw in the French capital. That incident recalled two other attacks on soldiers providing security at prominent locations around Paris, one at the Louvre museum in February and one at Orly airport in March.More news: Oakland Raiders to make Derek Carr highest paid quarterback in NFL
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