One police officer is dead, two other officers are seriously injured, and a bystander is also wounded, following a shooting in Paris, France.
One attacker has been shot dead, and another assailant is on the run.
The incident took place on the central Parisian boulevard of Champs-Elysees.
The attackers, who were in a car, opened fire on a police car at a red light, killing an officer inside.
Early reports suggest the weapon used in the attack was a Kalashnikov automatic rifle.
The French Interior Ministry said police officers guarding the area were deliberately targeted.
Police say the killed gunman was known to security services. His house, in the east of Paris, was raided after the attack.
The second attacker was believed to have entered Paris by train from Brussels, Belgium. A warrant has been issued for his arrest.
Prosecutors have opened a terrorism investigation into the attack, and French President Francois Hollande says he's convinced the circumstances point towards terrorism.
Islamic State has claimed responsibility for the attack, but its involvement is yet to be confirmed by officials.
The attack came three days before the first round of balloting in France's tense presidential election. The major candidates have suspended their campaigns.
Helicopters were seen flying low over central Paris, and the Champs-Elysees, one of the world's most prestigious boulevards, had been closed off.
People were warned to avoid the area.