One police officer is dead and two seriously wounded after a shooting on Paris’ famous Champs Elysees, in an incident that left one attacker dead. The assailant reportedly targeted a police vehicle. Authorities say a bystander was also wounded.

French prosecutor Francois Molins said the authorities have identified the shooter and are assessing whether the attacker had accomplices. Raids and searches were ongoing, Molins said.

ISIS very quickly claimed responsibility for the attack, through the group’s semi-official news agency Amaq, reports the SITE intelligence group.

French President Francois Hollande had already said that the authorities suspect the attack was “of a terrorist nature,” according to a French 24 translation of his news conference Thursday night. He says counterterrorism authorities are investigating.

The shooting comes just days before first-round votes are cast Sunday in France’s closely watched presidential election. At the time of the shooting, all 11 presidential candidates were appearing on television.

Earlier this week, in a separate incident, French authorities arrested two men in Marseille, saying they were suspected of planning an “imminent” attack ahead of the election and were found in possession of an arsenal of weapons.

France has been under a state of emergency since 2015, because of a series of deadly terrorist attacks over the past several years. In July, an attacker in Nice drove a truck into a crowd celebrating Bastille Day, killing more than 80 people and injuring hundreds before he was fatally shot by police.