PARIS (CNN) -- One police officer and an attacker were killed in a Thursday night shooting on the Champs-Elysees in Paris, the French Interior Ministry said.
A car stopped at 102 Champs-Elysees in front of a police van, ministry spokesman Pierre Henry Brandet said. A man emerged from the car and opened fire on the van with an "automatic weapon," he said. The police returned fire and killed the attacker.
The ministry said one police officer was killed. It's not known if the attacker was a man or a woman.
The BBC also reported that the gunman was dead.
French President Francois Hollande said that he was "convinced" that the event was terror-related.
The Islamic State group has claimed responsibility for Thursday's attack, however it should be noted that ISIS has claimed responsibility or attacks it had no role in conducting.
French anti-terror prosecutors and the National Intelligence Service are opening an investigation to determine the nature of the incident, the Paris Prosecutor's Office said in a text to CNN. This means they are looking at terror as a possible motive in the attack.
CNN affiliate BFMTV is reporting that Paris anti-terror forces are heading the investigation, but Police Secretary Yvan Assioma told reporters there were "no theories" about whether this was a criminal act or an act of terror.
BFMTV also reported an unidentified man was hit by "cross-fire" in the Champs-Elysees area. BFMTV has not specified if the unidentified man was the attacker or a bystander.
The shooting shut down the normally busy Champs-Elysees, one of the top tourist attractions in Paris, and video showed the avenue empty of residents and tourists but teeming with security officers at 9:30 p.m. All businesses in the area closed.
At least three underground train stations of the Paris Metro -- the Champs-Elysees-Clemenceau, George V and F. Roosevelt stations -- have been "closed off" near the site of the police operation on the Champs-Elysees in Paris, BFMTV reports.
Paris resident Daoud Kal, 29, said he was walking in the area near a metro station when he heard four to five shots. He looked around, but couldn't identify where the shots were coming from. People panicked and ran away from the scene and he joined them.
The CNN Paris bureau is on this street and staffers reported hearing a dozen shots. At least 20 police vehicles were seen on the street.
Officers could be seen forcibly removing innocent citizens from the area as they attempted to get them to safety.
President Donald Trump, speaking at a news conference in Washington with the visiting Italian Prime Minister, offered condolences to the people of France after the shooting in Paris, saying it "looks like another terrorist attack."
"What can you say? It never ends," the President said.
The shooting comes three days before French general elections and Paris was already in a state of heightened alert. French politicians immediately spoke out on social media.
French far-right presidential candidate Marine Le Pen tweeted, "My emotions and solidarity for the police, once again targeted."
Conservative French presidential hopeful Francois Fillion tweeted, "Paying homage to police who give their lives to protect ours, #ChampsElysees."
The Champs-Elysees, a top tourist attraction in Paris, is a main road lined with restaurants, cafes, exclusive designer boutiques and tourist shops.
At one end is the Arc de Triomphe, surrounded by a several-lane-wide roundabout, and the other end stops at the Place de la Concorde, known for its obelisk monument.
The presidential palace, the Elysee, is a few blocks away.
French police tweeted, "Police intervention underway in the area of the #ChampsElysees avoid the sector and follow the instructions of the police forces."
The US State Department put out a cautionary tweet, saying: "If you're in #Paris, monitor local news. #ChampsElysees has been closed. Authorities are telling people to avoid the area after a shooting."