BFMTV was the first to report the shooting on one of the Paris' most famous boulevards.
Paris police spokeswoman Johanna Primevert says unidentified gunman appeared to be alone when he allegedly opened fire on a police vehicle.
President Francois Hollande is due to speak after holding a crisis meeting with Prime Minister Bernard Cazeneuve and Interior minister Matthias Fekl.
"I was in a panic, and I ran too", he said. "There were tens, maybe even hundreds of them".
SO-CALLED Islamic State has claimed responsibility for a central Paris shooting which left a police officer dead and two others seriously wounded.
Trump is also offering condolences from the U.S.to the people of France. Trump said. "It just never ends".
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Guardiola's men also have the FA Cup to look forward to, with a game against Arsenal scheduled in the semi-finals next weekend. Leroy Sane grabbed a second moments before Aguero chipped in with his 29th goal of the season to seal victory.
After the loud bangs, she says: 'A sudden noise where we were was mistaken for gunfire and had police shouting us off the street.
Pierre-Henry Brandet, the interior ministry spokesman, confirmed an attacker was shot dead by police and the area remains cordoned off.
The Avenue des Champs-Élysées is an avenue in the 8th arrondissement of Paris, 1.9 kilometres long and 70 metres wide, running between the Place de la Concorde and the Place Charles de Gaulle, where the Arc de Triomphe is located.
The avenue has been closed and authorities are telling people to avoid the area.
A auto stopped at 102 Champs-Elysees in front of a police van, ministry spokesman Pierre Henry Brandet said. It saw the assailant getting off a auto and opening fire at officers inside another vehicle.
One officer was killed and another was wounded.
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Almost half a million people were renting with 326,493 households in a lease with a private landlord, the report said. The equivalent age in previous censuses was 32 years in 2011, 28 years in 2006, 27 years in 2002 and 26 years in 1991.
The attacker is believed to have deliberately targeted the officers, according to reports, and was known to security services.
He says police are securing the area but there is "no other police operation underway" in the popular area.
The incident came just two days after police arrested two men in southern Marseille with weapons and explosives who were suspected of preparing an attack to disrupt the first round of the election in three days. Two police officials, speaking on condition of anonymity because they weren't authorized to publicly discuss the investigation, said the attacker had been flagged as an extremist.
One witness told French television station BFM that she heard a shooting, saw a man's body on the ground and the area was quickly evacuated by police.
It happened as presidential candidates made their last pitches in a TV appearance before Sunday's election.
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In a statement, DCMJ co-founder Nikolas Schiller called the arrests "an unlawful violation of our most basic civil liberties". He and others planned to protest for marijuana reforms on Monday by lighting up on the Capitol grounds.