For more than four hours, Noemi shivered through the biting chill and the abject terror of being hidden away inside the refrigerated cellar of a kosher grocery store as a murderous gunman rampaged above.

The cold-storage room had been her salvation when she dashed inside Friday afternoon, escaping the bullets that felled others. But as night fell, she huddled with fellow hostages and worried that it would become her death chamber.

“We’re very afraid, and we’re very cold,” Noemi told a friend, 29-year-old Anthony Ravaux, in a phone call just after 5 p.m. “Tell the police to hurry.”

Minutes later, right at sundown, dozens of heavily armed officers stormed the store in a furious assault of smoke, sound and fire. The hostages made a desperate run for the doors as officers shot the gunman dead, ending the standoff.

But the siege of the Hyper Cacher market, in eastern Paris’s Porte de Vincennes neighborhood, had already taken a terrible toll, with four hostages dead and France’s half-million-strong Jewish community feeling newly vulnerable to the scourge of radical Islamist violence.

Two hostage situations related to Wednesday's massacre at the satirical newspaper Charlie Hebdo ended Friday evening Paris time when police simultaneously stormed both sites. All three suspects were killed.

In three days that traumatized a nation, three men with deep histories of association with terrorist organizations carried out three deadly attacks: The first against a newspaper, the second against a police officer and the third against a kosher grocery store.

The last, said President François Hollande in an address to the nation Friday evening, was unquestionably “an anti-Semitic attack.”

In Porte de Vincennes — a stately neighborhood of low-slung 19th-century buildings that is home to a heavy mix of both Jews and Muslims, many of whom share North African heritage — there was no doubt.

The hostage-taking began just after noon, when Amedy Coulibaly, 32, a French citizen of Senegalese descent, walked into the store and began to shoot. The attack played out hours before the start of the Jewish Sabbath on Friday night, a particularly busy time for a kosher shop.

As police quickly established a cordon around the building, residents on the outside were left to wonder what had become of friends and colleagues trapped within.

Two women who worked at the store but were off at the time of the attack sobbed as they frantically dialed the phone numbers of friends. One said she had received a call from a colleague who could only get out the words “people are shooting” before the line was cut.

“They were only targeted because they were Jewish,” the woman, who declined to give her name, said of her colleagues. “They’re just normal people trying to do their jobs.”

Malik Zadi, a 25-year-old Muslim of Algerian heritage, agreed that the attack was aimed at Jews but noted that Muslims were likely to be hostages, as well.

“It’s a kosher store, but not only Jews go there. I go there,” Zadi said. “In this neighborhood, there are Muslims, Jews, Christians. It’s like Paris. It’s a melting pot. Cohabitation.”

This week, that cohabitation is being challenged like never before, with attacks that have torn at the foundations of French society.

The assault has come from three men who were all nurtured in that society but who became alienated enough to want to tear it down.

Amid the standoff at Hyper Cacher, Coulibaly told a French television station that he had shot dead a Paris policewoman on Thursday and that he was working in concert with Said and Chérif Kouachi, the brothers implicated in Wednesday’s attack on the satirical newspaper Charlie Hebdo.

“We coordinated from the beginning, when they started with Charlie Hebdo and I started with the police,” Coulibaly told the station, BFM TV.

As he spoke, the Kouachi brothers were orchestrating their own high-stakes drama 25 miles away at a mom-and-pop printing business in the village of Dammartin-en-Goele.

But unlike the brothers, who had taken a single hostage when they commandeered the commercial building Friday morning — and later let him go — Coulibaly had an entire grocery store full of terrified employees and customers.

There were 16 hostages, including children, Coulibaly told the station. He boasted that he had already killed four people, and police said he was threatening to shoot more if they staged a raid against his accomplices in Dammartin.

In fact, Coulibaly had significantly more hostages than he knew: the ones who had dashed into the cold-storage room had apparently escaped his detection.

But Noemi and the others huddled inside had no way of knowing that. They felt a jolt of apprehension with every sound from above, and they scoured the storage-room floor for empty boxes and other possible places to hide.

“Don’t panic,” Ravaux told Noemi, whose last name he did not want to reveal, when she reached him by phone. “The police will do their best.”

Ravaux, who had walked out of the store five minutes before Coulibaly burst in, told her to conserve her phone’s battery, and the two hung up.

Within minutes, the streets echoed with three loud booms as police tossed stun grenades and began their assault. After a pause, the earth shook with 30 seconds of sustained gunfire. Blocks away, parents shepherded screaming children into the shelter of nearby doorways.

And then, silence.

More than an hour after the raid, Ravaux said he believed that his friend had survived. But he could not reach her by phone.

“I hope she’s with the police,” he said.

Officials said that the Paris raid and a nearly simultaneous shootout with the Kouachi brothers in Dammartin left all three assailants dead, allowing the surviving hostages to go free. In his speech to the nation, Hollande praised law enforcement officers for their work and said France would not be divided by racism or anti-Semitism.

But on the streets of Porte de Vincennes, residents expressed a gnawing fear that the events of the past three days had unleashed a wave of violence with no end.

“This is only the beginning for what’s awaiting France,” said Sam Cohen, a 22-year-old who wore a black hoodie atop his black kippah. “Everyone’s going to grab a weapon, and there will be more and more dead every day.”

Michael Birnbaum and Cléophée Demoustier contributed to this report.