The leader of the far-right National Front party in France condemned calls to prevent her from becoming French president and to support her rival, Emmanuel Macron.
The shooting on the Champs-Élysées, which killed an officer and wounded three others, unsettled France just days before the first round of the presidential election.
The police shut down the Champs-Élysées after a shootout between officers and a suspected assailant days before France holds the first round of presidential election.
After recent electoral upheavals, including the victory of Donald J. Trump and the vote for “Brexit,” the world is waiting to see which way the French will lean.
The interior minister said that the two men, arrested in Marseille, were “suspected of wanting to imminently commit a violent action.”