A handwritten note praising the Islamic State group was found near the attacker who shot dead a police officer and wounded two others on Paris’s Champs-Elysees, a source close to the probe said Friday.

In addition to the note near the body of 39-year-old Frenchman Karim Cheurfi, authorities found a Koran in his vehicle at the scene of Thursday’s attack, the sources told AFP.

After killing the officer and injuring two of his colleagues just a few hundred meters (feet) from the Arc de Triomphe, the gunman was shot dead in return fire while trying to flee on foot.

The killer identified by French authorities was known to anti-terror police, sources told AFP. He had been arrested in February on suspicion of plotting to kill police officers but released for lack of evidence.

This photo provided by the AP on the condition that its source not be revealed, shows Karim Cheurfi. Police have searched a home in a suburb east of Paris believed linked to the attack on police on the Champs-Elysees. (AP Photo)

This photo provided by the AP on the condition that its source not be revealed, shows Karim Cheurfi. Police have searched a home in a suburb east of Paris believed linked to the attack on police on the Champs-Elysees. (AP Photo)

He had been convicted in 2005 on three counts of attempted murder, including two targeting police officers, sources said. Police were questioning three people from his entourage.

A statement by IS’s propaganda agency Amaq said the attacker was one of its “fighters”, identifying him as “Abu Yussef the Belgian.”

However, Belgium’s interior minister said Islamic State gave a false name for the man who carried out the attack.

Islamic State’s claim of responsibility came just a few hours after the attack — far more quickly than other similar claims — and the statement gave the attacker a pseudonym that would mean he was Belgian or had ties to Belgium.

Belgian Interior Minister Jan Jambon said Friday, “The guy who yesterday did the act was not a Belgian. He was French.”

Asked about the Abu Yussef Al-Beljiki pseudonym given by IS, Jambon said he “is certainly not the guy who committed the crime yesterday.”

IS has been losing territory in Iraq and Syria and has seen the number of foreign recruits, notably from Europe, dwindle.