An attacker crying "Allahu Akbar" killed one person and wounded four others on the streets of Paris Saturday evening before being shot dead by police.
Here is what we know so far:
Shortly before 9pm (1900 GMT) a knife-wielding attacker struck on Rue Monsigny, close to Place de L'Opera, an area of central Paris filled with restaurants, bars and tourist attractions.
Two witnesses and a judicial source said the man was shouting "Allahu Akbar (God is greatest) during the attack.
Many described scenes of panic as Parisians realised a potential terror attack was underway in a city that has been hit by multiple deadly jihadist assaults in recent years.
"I was taking orders and I saw a young woman trying to get into the restaurant in panic," Jonathan, a waiter at a Korean restaurant, told AFP. The woman was bleeding and the attacker appeared behind her. He said a young man tried to fend off the attacker who then fled.
"The attacker entered a shopping street, I saw him with a knife in his hand," he said. "He looked crazy".
Who were the victims?
According to sources with knowledge of the case, the man attacked random people in the street. The dead victim was a man in his 30s. A 34-year-old man and a 54-year-old woman were seriously wounded and rushed to hospital.
A 26-year-old woman and a 31-year-old man were slightly wounded.
French Interior Minister Gerard Collomb later told reporters that all four were out of danger.
"I have just seen the person who was most seriously injured, she is better, she is saved," he said.
What was the police response?
French Prime Minister Edouard Philippe said police were on the scene "within five minutes" of the attack. Some nine minutes later the assailant was dead, he added.
A police source told AFP one officer tried to restrain the attacker with a taser but when that failed a colleague shot the man dead.
"The speed of the response obviously avoided a heavier toll," Philippe said.
What do we know about the attacker?
At the moment, not a great deal. Investigators said the assailant carried no identifying documents on him. A source with knowledge of the case told AFP he was a young man with brown hair and a beard who was dressed in black tracksuit trousers.
Authorities are treating the attack as terror related, primarily because witnesses described him shouting "Allahu akbar", a refrain commonly used by violent jihadists when carrying out attacks.
The Islamic State group claimed responsibility, according to the SITE monitoring group, but provided no corroborating proof.