Paris police say that a gunman killed one police officer and wounded another before being killed himself in an attack on the Champs-Elysees shopping district.
Paris police spokeswoman Johanna Primevert said that the attacker targeted police guarding the area near the Franklin Roosevelt subway station on Thursday night at the centre of the avenue popular with tourists.
The attack came three days before the first round of France’s tense presidential election.
Security is high around the vote after France has been attacked in recent years.
Police had arrested two men on Tuesday in what they described as a thwarted terror attack.
The incident recalled two recent attacks on soldiers providing security at prominent locations around Paris, one at the Louvre museum in February and one at Orly airport last month.
A witness identified only as Ines told French television station BFM that she heard a shooting and saw a man’s body on the ground before police quickly evacuated the area, where she works in a shop.
A French television station hosting a televised event with the 11 candidates running for president briefly interrupted its broadcast to report the shootings.
None of the candidates immediately commented.
The French Interior Ministry said the attack deliberately targeted police officers guarding the area.
Spokesman Pierre-Henry Brandet said on BFM television that a man came out of a car and opened fire on a police vehicle.
Mr Brandet said the police officers were “deliberately” targeted.
He said police were securing the area but there is “no other police operation under way” there.
He said it was too early to say whether the attacker might have had an accomplice, and said authorities were studying multiple potential motives.
US President Donald Trump, speaking in Washington during a news conference with Italian Prime Minister Paolo Gentiloni, said the shooting “looks like another terrorist attack” and sent his condolences to France.