PARIS (TIP): A lone gunman opened fire on police on Paris’ iconic Champs-Elysees boulevard Thursday night, killing one officer and wounding three people before police shot and killed him. The Islamic State group claimed responsibility for the attack, which hit just three days before a tense presidential election.

Security already has been a dominant theme in the campaign, and the violence on the sparkling avenue threatened to weigh on voters’ decisions. Candidates canceled or rescheduled final campaign events ahead of Sunday’s first round vote.

One officer was killed and two police officers were seriously wounded when the attacker emerged from a car and used an automatic weapon to shoot at officers outside a Marks & Spencer’s department store at the center of the Champs-Elysees, anti-terrorism prosecutor Francois Molins said.

A female foreign tourist also was wounded, the officer said.

Police and soldiers sealed off the area, ordering tourists back into hotels and blocking people from approaching the scene.

Emergency vehicles blocked the wide Champs-Elysees, an avenue lined with boutiques and normally packed with cars and tourists that cuts across central Paris between the Arc de Triomphe and the Tuileries Gardens. Subway stations were closed off.

The gunfire sent scores of tourists fleeing into side streets.

French President Francois Hollande said he was convinced the circumstances of the attack in a country pointed to a terrorist act. Mr. Hollande held an emergency meeting with the prime minister on Thursday night and planned to convene the defense council on Friday morning.

Speaking in Washington during a news conference with Italian Prime Minister Paolo Gentiloni, U.S. President Donald Trump said the shooting “looks like another terrorist attack” and sent condolences to France.

Conservative contender Francois Fillon, who has campaigned against “Islamic totalitarianism,” said on France 2 television that he was canceling his planned campaign stops on Friday.

Far-right candidate Marine Le Pen, who campaigns against immigration and Islamic fundamentalism, took to Twitter to offer her sympathy for law enforcement officers “once again targeted.” She canceled a minor campaign stop, but scheduled another.

Centrist candidate Emmanuel Macron offered his thoughts to the family of the dead officer.

Socialist Benoit Hamon tweeted his “full support” to police against terrorism.