PARIS — A gunman holding at least five hostages in a Paris kosher market has threatened to kill them if French authorities launch an assault on two cornered al-Qaida-linked brothers suspected in a newspaper massacre, a police official said Friday.

Terrorists linked to each other seized hostages at two locations around Paris on Friday, facing off against thousands of French security forces as the city shut down a famed Jewish neighborhood and scrambled to protect residents and tourists from further attacks.

France has been high alert for more attacks since the country’s worst terror attack in decades — the massacre Wednesday in Paris at the satirical newspaper Charlie Hebdo that left 12 people dead.

The two sets of hostage-takers apparently know each other, said a police official who was not authorized to discuss the rapidly developing situations with the media.

The Paris mayor’s office announced the closure of 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 (a half mile) away from Charlie Hebdo’s offices.

Two brothers linked to al-Qaida grabbed a hostage early Friday and were cornered by police inside a printing house in Dammartin-en-Goele, northeast of Paris. They are believed responsible for the attack that decimated Charlie Hebdo’s staff and left two police officers dead.

In addition, the police official said the gunman holding at least five hostages Friday inside a kosher grocery store in eastern Paris is believed responsible for the roadside killing of a Paris policewoman on Thursday. Authorities released a photo of him and a female accomplice.

At the store near the Porte de Vincennes neighborhood, the gunman burst in shooting just a few hours before the Jewish Sabbath began, declaring “You know who I am,” the official recounted.

The police official said several people had been wounded when the gunman opened fire in the kosher market but were able to flee and get medical care. It was not clear whether there were other wounded inside the market, or whether the woman listed as the gunman’s accomplice in a police bulletin was inside with him.

Police SWAT squads descended on the area and France’s top security official rushed from to the scene. The attack came before sundown when the store would have been crowded with shoppers.

Paris police had released a photo of Amedy Coulibaly and a second suspect, a woman named Hayet Boumddiene, who the official said is the market gunman’s accomplice. Police said 100 students were under lockdown in schools nearby and the highway ringing Paris was closed.

Hours before and 40 kilometers (25 miles) away , a convoy of police trucks, helicopters and ambulances streamed toward Dammartin-en-Goele, a small industrial town near Charles de Gaulle airport, to seize the Charlie Hebdo suspects, who had hijacked a car in a nearby town after more than two days on the run.

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