The shooting on the final day of the presidential campaigning in France's pivotal presidential election caused the candidates to suspend last-minute pitches before the Sunday vote.
However previous attacks that have taken place soon before elections, including the November 2015 attacks in Paris ahead of regional polls and the shooting in a Jewish school before the 2012 presidentials, did not appear to change the course of those ballots in favor of those espousing tougher national security.
As Paris got back to business, municipal workers in white hygiene suits were out before dawn to wash down the sidewalk where the assault took place - a scene now depressingly familiar after multiple attacks that have killed more than 230 people in France over two years.
The men were said to be French nationals who had been radicalised and were believed to have links to IS.
"Nothing must hamper this democratic moment, essential for our country", Prime Minister Bernard Cazeneuve said after a high-level meeting Friday that reviewed the government's already heightened security plans for the two-round vote that begins Sunday.
A French policeman was shot dead and two others were wounded in Thursday night's attack in central Paris.
The gunman who killed a police officer in Paris on Friday night has been named as 39-year-old Frenchman Karim Cheurfi by Associated Press.
In a statement from its Amaq news agency, IS group gave a pseudonym for the shooter, Abu Yusuf al-Beljiki, indicating he was Belgian or had lived in Belgium. A second suspect handed himself in to Belgian police on Friday.
Macron, Le Pen to face off in second round of French election
Le Pen, who leads the National Front, has made immigration and security a core part of her campaign. "Naivety is over", she said. Although there are 50,000 police on the streets, CNN's Bitterman points out, there are 60,000 polling stations.
Police tape surrounded the quiet, middle-class neighborhood and anxious neighbors expressed surprise at the searches.
Authorities are trying to determine whether "one or more people" might have helped the attacker, Brandet said.
Earlier this week French authorities arrested two men in Marseille who were allegedly planning an attack in a run-up to the election.
As of Friday morning local time, leading candidates François Fillon, Emmanuel Macron and Marine Le Pen had all canceled campaign events, with Macron citing the extra burden policing political rallies placed on the security services. It recalled two recent attacks on soldiers providing security at prominent locations around Paris: one at the Louvre museum in February and one at Orly airport last month.
The paper also reported that Macron's chief rival for the presidency, National Front leader, Marine Le Pen, would not campaign Friday out of respect for the victims.
Three of 11 presidential candidates have halted campaigning after the shooting, which came three days before French voters go to the polls. The two-round presidential election is set for April 23 and May 7. "It will require an unyielding determination and a cool head". "Anyone who pretends (otherwise) is both irresponsible and deceitful".
The Islamic State group claimed responsibility. She canceled a minor campaign stop, but scheduled another.