The worst terrorist attacks France has seen in decades left at least 20 people dead, including the three gunmen. The fate of a fourth suspect — a female accomplice of the market attacker — remained unclear.

At least seven people were killed Friday — the three terrorists and at least four hostages — a policewoman was killed Thursday and 12 people were massacred in the Paris newspaper attack Wednesday. Sixteen hostages were freed Friday, one from the printing plant where the two brothers were holed up and 15 others from the Paris grocery store.

Paris shut down a famed Jewish neighborhood amid fears that a wider terror cell might launch further attacks.

French President Francois Hollande urged his nation to remain united and alert. Calling the grocery attack “a terrifying anti-Semitic act,” he said the terrorists were “fanatics who have nothing to do with the Islamic religion.”

“The threats facing France are not finished,” he said. “We must be vigilant.”

The four attackers had ties to each other and to terrorism that reached back years and extended from Paris to al-Qaida in Yemen. They epitomized Western authorities’ greatest fear: Islamic radicals who trained abroad and came home to stage attacks.

Said and Cherif Kouachi, the brothers who attacked the Charlie Hebdo satirical weekly, came out with guns blazing Friday evening after an all-day hostage siege at a printing plant northeast of Paris, a French police official said. They were killed and their hostage was freed, authorities said.

An accomplice, Amedi Coulibaly, took hostages Friday afternoon at a kosher grocery in the Porte de Vincennes neighborhood in Paris — then died in a nearly simultaneous raid there, said Gael Fabiano of the UNSA police union. Coulibaly had threatened to kill his hostages if French authorities launched an assault on the two brothers, a police official said.

A French television news network spoke directly with two of the terrorists Friday before they died. BFM television said it spoke with Cherif Kouachi as he and his brother were cornered near Charles de Gaulle airport and he told the station they were financed and dispatched by al-Qaida in Yemen.

The station also said it spoke with Coulibaly, who said the three men were coordinating and that he was with the militant Islamic State group. The organizations are normally rivals.

France has been on high alert since the Charlie Hebdo massacre left 12 people dead. The next day, a gunman shot a policewoman to death in a gunfight just south of Paris. Police later identified the gunman as Coulibaly, who had been a co-suspect with Cherif Kouachi in a court case involving terrorism that never made it to trial.

The Kouachi brothers led police on a chase around northeast France, robbing a gas station Thursday and stealing a car Friday morning before seizing hostages at a printing plant in Dammartin-en-Goele, a small industrial town near Charles de Gaulle airport.

Friday afternoon, explosions and gunshots rang out and white smoke rose outside as a police SWAT team clambered onto the roof. Audrey Taupenas, spokeswoman for the town near the Charles de Gaulle airport, said the brothers had died in the clash.

“They said they want to die as martyrs,” Yves Albarello, a local lawmaker inside the command post, told French television station i-Tele.

Trying to fend off further attacks, the Paris mayor’s office shut down all shops along Rosiers Street in the city’s famed Marais neighborhood in the heart of the tourist district. Hours before the Jewish Sabbath, the street is usually crowded with shoppers — French Jews and tourists alike. The street is also only a kilometer (half a mile) from Charlie Hebdo’s offices.

At the kosher grocery near the Porte de Vincennes neighborhood in Paris, the gunman burst in shooting just a few hours before the Jewish Sabbath began, declaring “You know who I am,” the official recounted. The attack came before sundown when the store would have been crowded with shoppers.

Paris police released a photo of Coulibaly and his wife, Hayet Boumddiene, who the official said was his accomplice.

Several people wounded when the gunman opened fire in the grocery store were able to flee and get medical care. One hundred students were locked down in nearby schools and the highway ringing Paris was closed.

Cherif Kouachi, 32, was convicted of terrorism charges in 2008 for ties to a network sending jihadis to fight U.S. forces in Iraq.

A Yemeni security official said his 34-year-old brother, Said Kouachi, is suspected of having fought for al-Qaida in Yemen. Another senior security official said Said was in Yemen until 2012.

Both officials spoke to The Associated Press on condition of anonymity because of an ongoing investigation into Kouachi’s stay in Yemen.

Both brothers were also on the U.S. no-fly list, a senior U.S. counterterrorism official said, speaking on condition of anonymity because the official was not authorized to discuss foreign intelligence publicly.

The satirical weekly Charlie Hebdo had long drawn threats for its depictions of Islam, although it also satirized other religions and political figures. The weekly paper had caricatured the Prophet Muhammad, and a sketch of Islamic State’s leader was the last tweet sent out by the irreverent newspaper, minutes before the attack.

Eight journalists, two police officers, a maintenance worker and a visitor were killed in the newspaper attack, including the paper’s editor. Charlie Hebdo plans a special edition next week, produced in the offices of another paper.

Authorities around Europe have warned of the threat posed by the return of Western jihadis trained in warfare. France counts at least 1,200 citizens in the war zone in Syria — headed there, returned or dead. Both the Islamic State group and al-Qaida have threatened France, home to Western Europe’s largest Muslim population.