A man stabbed a police officer at her station in western France, then shot two other officers before being killed in a shootout with police, authorities said.
The motive for the violence is unclear, and the man's identity is still being verified, officials said.
The three officers were wounded but are not in life-threatening condition, police said.
After stabbing the first police officer in her station in the Nantes suburb of La Chapelle-sur-Erdre, the assailant took her gun and fled, according to officials.
Police deployed helicopters, search dogs and more than 200 officers to find the suspect, and closed nearby schools and stores.
When he was located, he fired on officers trying to arrest him, police said.
He was wounded in an ensuing shootout and died on Friday afternoon, according to an official.
Police and ambulances blocked roads in the normally quiet residential area after the stabbing.
Domestic security and attacks on police are a big political issue ahead of regional elections next month and a presidential election next year.
The incident follows a series of terrorist attacks across France, including a female police worker being murdered by an Islamist knifeman in the Paris suburb of Rambouillet last month.
Friday’s incident saw the man ‘slash the woman officer several times with a knife inside the police headquarters,’ according to a local police spokesman.
‘The man then grabbed the officer’s pistol and fled the scene. He is being hunted by other officers,’ the spokesman added.
The wounded female officer, who has not been named, was rushed to hospital with a ‘very serious thigh injury which could be life threatening,’ said the source.
There was no initial clue as to the knifeman’s motives, a police spokesman said.
Schools in the area were under police protection, a police source added.
The woman police officer, who is in her 40s, was wounded ‘in the thigh, arms and legs,’ said a spokesman for the town hall in La Chappelle-sur-Erdre.
Witnesses said they saw the attacker get into a VW Golf after the attack, but then got out of the car and fled on food.
‘He was brandishing the pistol taken from the police officer he stabbed,’ said the town hall spokesman.
Heavily armed GIGN officers lead the manhunt, along with police and gendarmes, and a helicopter was deployed, the spokesman added.
The Rambouillet attack was carried out by a 36-year-old immigrant from Tunisia, who was himself blasted to death by police after killing the officer.
It followed six years of savage Islamist attacks in France, including the beheading of schoolteacher Samuel Paty by a Russian-born terrorist in October last year.
The deadliest single terrorist attack ever in the country came in November 2015 when 130 people were killed in Paris.
Suicide bombers pledging allegiance to ISIS targeted the Stade de France, cafes, restaurants and the Bataclan music venue, where 90 died.
Earlier in the year, two Paris-born gunmen linked to Al-Qaeda broke into the offices of the Charlie Hebdo satirical magazine, leaving 12 dead and 11 wounded.
In July 2016, 86 people were killed and more than 400 injured when a 19-tonne truck was deliberately driven into crowds on the seafront promenade at Nice, in the South of France.
The terrorist turned out to be a radicalised Tunisian immigrant who was shot dead by police.
During the same month, two Isis terrorists murdered an 86-year-old Catholic priest during a church service in Normandy.
There have been frequent knife attacks on the forces of law and order, leading to the deaths of serving police.
In October 2019, a radicalised computer operative working at the Paris Prefecture in central Paris stabbed four of his colleagues to death.
The attacker – who was also shot dead – turned out to be a Muslim convert who kept extremist Al-Qaeda and Islamic State literature and images on his computer.