Police officer and gunman killed in central Paris shooting Police officer and gunman killed in central Paris shooting

Police secure the Champs-Elysees after one police officer was killed and another wounded in a shooting in Paris, France, April 20, 2017. REUTERS/Christian Hartmann

• A gunman killed a police officer and injured two more in central Paris
• The attacker was killed by return fire
• Police are unsure of the motive, although some said the shooting was a terrorist act
• The incident happened three days before the French presidential election begins
• US President Donald Trump commented on the attack at a press conference

One police officer was killed and two more were injured in a shooting in Paris on Thursday, multiple news outlets are reporting.

According to The Guardian, an attacker opened fire on a police van on the Champs-Elysees in central Paris. Reuters reported the gunman was using a machine gun. He tried to run away but was killed by return fire.

The two injured officers are in serious condition, Reuters reported, citing the French Interior Ministry, despite prior reports that one of them had died. 

According to police, the shooting was "very probably a terrorist act," ITV reported. Reuters cites three police sources who say it may have been an attempted armed robbery. But French Interior Ministry spokesman told Reuters it was too early to identify a motive.

The attacker was known to police, a source told The Guardian, and authorities were searching his east Paris home.

Police closed off the Champs-Elysee and security vehicles are on the scene, CNN reported. Police are urging the public to avoid the popular tourist area.

#ChampsElysees closed. Riot police on ground in #paris pic.twitter.com/JCWovTqpb9

— Melissa Bell (@MelissaBellCNN) April 20, 2017

Still on Champs-Elysess. It's getting pretty scary #paris pic.twitter.com/GbPeZuaryV

— Allie Fowler (@historynerd94) April 20, 2017

Security in Paris was increased this week ahead of the French presidential election on Sunday. Two men were arrested on Tuesday for planning an "imminent and violent attack" before the vote. There is no information linking Tuesday's arrests with Thursday's shooting, The Guardian reported.

US President Donald Trump was briefed on the attack and acknowledged it during a press conference on Thursday.

"Condolences from our country to the people of France," Trump said. "It's a terrible thing that's going on in the world today.

"It looks like another terrorist attack. What can you say — it never ends," he added.

This story is developing.