(AP) -- France's government urged the nation to remain vigilant Saturday, as thousands of security forces try to thwart new attacks and hunt down a suspected accomplice in a rampage by terrorists linked to al-Qaida in Yemen that scarred the nation and left 20 dead.

Hundreds of thousands of people marched Saturday in cities from Toulouse in the south to Rennes in the west to honor the 17 victims of three attackers, killed by police after three days of bloodshed at the offices of a satirical newspaper, a kosher supermarket and other sites around Paris.

The sense of relief was tinged with sorry and worry. In Paris, security forces guarded places of worship and tourist sites, and prepared for what's likely to be a huge silent march Sunday to show unity against extremists. Two dozen world leaders, including German Chancellor Angela Merkel and British Prime Minister David Cameron, are among the many expected to join.

French Interior Minister Bernard Cazeneuve said authorities will do everything to ensure security at the event. Speaking after an emergency meeting called by French President Francois Hollande on Saturday morning, Cazeneuve called for "extreme vigilance," saying that "given the context, we are exposed to risks."

Al-Qaida's branch in Yemen said it directed Wednesday's attack against the publication Charlie Hebdo to avenge the honor of the Prophet Muhammad, a frequent target of the weekly's satire.

In a sign of the tense atmosphere, a security perimeter was briefly imposed at Disneyland Paris on Saturday before being lifted, a spokeswoman said, without elaborating. Movement around the park was back to normal by early afternoon.

Cazeneuve said the government is maintaining its terror alert system at the highest level in the Paris region, and said investigators are focusing on determining whether the attackers were part of a larger extremist network.

Five other people are in custody as part of the investigation, and family members of the attackers are among several given preliminary charges so far.

French radio RTL released audio Saturday of the attacker, Amedy Coulibaly, who seized hostages in the kosher supermarket, in which he lashes out over Western military campaigns against extremists in Syria and Mali. He describes Osama bin Laden as an inspiration.

One of his hostages said on France 2 television Saturday that the gunman told them: "'Me, I'm not scared of dying. Either I die, or I get a 40-year prison sentence.'" The woman was identified only as Marie, and didn't show her face.

The focus of the police hunt is on Coulibaly's widow, Hayat Boumeddiene. Police named her as an accomplice and think she is armed.

"You must consider her as the companion of a dangerous terrorist who needs to be questioned," Christophe Crepin, spokesman for UNSA police union, told The Associated Press. "Since 2010, she has had a relationship with an individual whose ideology translates into violence and the execution of poor people who were just doing their shopping in a supermarket."

Jewish groups planned a vigil after sundown Saturday to mourn the four people killed at the kosher market.

Loyalists of al-Qaida and the Islamic State group extolled the attackers on Charlie Hebdo as "lions of the caliphate." They described the attack as revenge for the French satirical publication's mockery of Islam's Prophet Muhammad and France's military involvement in Muslim countries.

This week's drama, played out on live TV and social media, began with brothers Said and Cherif Kouachi methodically massacring 12 people Wednesday at the Charlie Hebdo offices.

They were cornered on Friday at a printing house in Dammartin-en-Goele near Charles de Gaulle Airport on Friday, prompting a daylong standoff with police.

Coulibaly shot a policewoman to death south of Paris on Thursday. The next day, he attacked the Paris kosher market, threatening more violence unless the police let the Kouachis go.

It all ended at dusk Friday with near-simultaneous raids at the printing plant and the kosher market in eastern Paris.

Four hostages were found dead at the market - killed by Coulibaly, prosecutors said. Sixteen hostages were freed, one from the printing plant and 15 from the store.

Witnesses and family members of survivors struggled Saturday to come to terms with what happened.

The family of a French Muslim police officer killed in the newspaper attack expressed anger at the viral spread of images of his death.

Ahmet Merabet's partner described seeing the images on television in a restaurant without realizing it was him. Video taken by an onlooker that surfaced on the Internet shows what appears to be a wounded Merabet on the pavement raising a hand as though appealing for mercy before he was fatally shot in the head.

The attack on the kosher market came before sundown on the Jewish Sabbath, when the store would have been crowded with shoppers, and Hollande called it "a terrifying anti-Semitic act."

Chaimae Bourahmaoui felt her apartment vibrate with bursts of gunfire from the kosher market three floors below her.

"I could no longer breathe. We heard the explosions. We were hostages since we didn't know if the terrorist had a bomb," she told AP.

The attackers epitomized Western authorities' greatest fear: Islamic radicals who trained abroad and came home to stage attacks.

A member of al-Qaida in the Arabian Peninsula gave a statement in English to the AP saying the group's leadership "directed the operations and they have chosen their target carefully."

According to a Yemeni security official, Said Kouachi is suspected of having fought for al-Qaida in Yemen. Another senior security official added that Said was in Yemen until 2012. Both officials spoke to the AP on condition of anonymity because of an ongoing investigation into Kouachi's stay in Yemen.

The attacks in France, as well as a hostage siege last month in Sydney and the October killing of a solder near Canada's parliament, prompted the U.S. State Department to issue a global travel warning for Americans. It also cited an increased risk of reprisals against U.S. and Western targets for the U.S.-led intervention against Islamic State group militants in Syria and Iraq.

The publication Charlie Hebdo had long drawn threats for its depictions of Islam, although it also lampooned other religions and political figures. Charlie Hebdo plans a special edition Wednesday, produced in the offices of another paper.