Authorities in Paris on Friday are investigating a home believed to be linked to the attack on police on the Champs-Elysees that resulted in the death of one officer.
Two police officials said the chief suspect in the fatal attack was a 39-year-old man from a suburb east of the French capital. Officials said the assailant was armed with an automatic firearm akin to a "war weapon."
The suspect's name was not publicly released. The Islamic State group claimed responsibility for the attack and gave a pseudonym for the shooter, Abu Yusuf al-Beljiki, indicating he was Belgian or had lived in Belgium. The attacker opened fire on a police van on the avenue before being killed.
The claim of responsibility came unusually swiftly for the group, which has been losing territory in Iraq and Syria.
Searches were conducted in at least one suburb east of Paris after Thursday's attack. Police tape surrounded the quiet, middle-class neighborhood in Chelles early Friday, and worried neighbors expressed surprise at the searches.
The police officials were not authorized to be publicly named discussing the ongoing investigation.
One police officer was killed and two others seriously injured when a gunman with an automatic weapon opened fire. Officers shot and killed the assailant.
Paris' iconic Champs-Elysees boulevard is reopen and picking up its usual early morning routine Friday. Delivery trucks were making their rounds. Traffic was going up and down the famous tree-lined street and police barriers have been taken down.
France's presidential candidates have expressed their solidarity with police forces.
The 11 candidates were appearing on a television program ahead of the first round of voting in the two-part election when the attack occurred.’
Conservative contender Francois Fillon said on France 2 television he was canceling his planned campaign stops on Friday. Far-right candidate Marine Le Pen took to Twitter to offer her sympathy for law enforcement officers "once again targeted."
The first round of the presidential race is scheduled on Sunday. The two top contenders will advance to a runoff on May 7.
U.S. Vice President Mike Pence says the shooting of police officers in Paris is the "latest reminder that terrorism can strike anywhere, anytime." He says the U.S. "will not relent in our effort to end terrorism."
Australia's prime minister has offered his country's prayers for police officers who were shot in Paris and urged Australians in Europe to be wary.
The Associated Press contributed to this report