PARIS (CNN) -- Blasts and gunfire could be heard moments ago near the kosher market in eastern Paris where authorities said hostages are being held, CNN's Jim Sciutto reported.
Two intense standoffs with gunmen are underway in and around Paris on Friday -- one involving the two brothers wanted in the Charlie Hebdo massacre and the other a hostage situation at a kosher grocery store.
Authorities have not said if or how the situations are related, but both underscored France's days-long nightmare and anti-terrorism fight.
Latest updates at 11:02 a.m. ET
STANDOFF IN DAMMARTIN-EN-GOELE
• Shots were heard shortly before 5 p.m. (11 a.m. ET) around the industrial area where the Kouachi brothers -- the suspects in the massacre at the offices of Charlie Hebdo -- are surrounded by law enforcement. Several large explosions were heard.
• One person is being held hostage in Dammartin-en-Goele, France Info radio reported, citing the French Interior Ministry.
• The gunmen are surrounded, French authorities said. Yves Albarello, who is in France's parliament, said on French channel iTele that the two suspects told police by phone that they wanted to die as martyrs.
• There had been no assault, nor any injuries or deaths, as of 1 p.m. (7 a.m. ET), Interior Ministry spokesman Pierre Henri Brandet said.
• A salesman, who identified himself only as Didier, told France Info radio that he shook one of the gunman's hands around 8:30 a.m. Friday as they arrived at a Dammartin-en-Goele printing business -- the same place where the Kouachi brothers are thought to be. Didier told the public radio station that he first thought the man, who was dressed in black and heavily armed, was a police officer.
As he left, the armed man said, "Go, we don't kill civilians." Didier said, "It wasn't normal. I did not know what was going on."
• Dammartin-en-Goele residents have been told to stay inside, and schools were put on lockdown, the mayor's media office told CNN on Friday. Shops in the town have been told to close.
GROCERY STORE HOSTAGE SITUATION
• The hostage-taker at the eastern Paris grocery store demanded freedom for the Kouachi brothers -- the suspects in the massacre at the offices of Charlie Hebdo -- witnesses said, according to Pascal Disand of the Alliance Police Union.
• Dozens of schools were placed under lockdown because of the hostage situation in eastern Paris, police said.
• At least one man -- suspected to be Amedy Coulibaly, 32, one of two people wanted in Thursday's deadly shooting of a policewoman south of Paris -- is thought to be holding six people in the kosher store near Porte de Vincennes in eastern Paris, police union spokesman Romain Fabiano told CNN affiliate BFMTV.
• Authorities haven't said how many are being held, or if anyone has been killed.
• Police anti-terror units raced to the scene of the hostage situation early Friday afternoon, while ambulances blared as they moved away from it. Roads around the area have been blocked off.
• Said Kouachi, one of the two brothers suspected of killing 12 people in and around the provocative satirical magazine Charlie Hebdo in Paris, spent several months in Yemen in 2011, receiving weapons training and working with al Qaeda in the Arabian Peninsula, which is based there, U.S. officials said Friday.
• French President Francois Hollande held a crisis meeting Friday afternoon with senior Cabinet members at the Elysee Palace in Paris. Those in attendance included Prime Minister Manuel Valls, Interior Minister Bernard Cazeneuve and Justice Minister Christiane Taubira, according to the French presidency.
• These aren't the only incidents occupying French authorities. So, too, is the fatal shooting of the policewoman Thursday in Montrouge, a southern suburb of Paris. On Friday, French police released photos of a man and a woman -- Coulibaly and Hayat Boumeddiene, 26 -- who they believe carried out this attack and are believed to be armed and dangerous.
Father: 'It's like a war'
Henri Dunant elementary school should be a place to learn, to play, to be a kid.
Not to hide in fear of killers on the loose. But that's what students did for hours Friday, there and at many other schools around Dammartin-en-Goele.
By late Friday afternoon, some of them were finally allowed to leave, though they weren't alone. Police officers accompanied the children -- holding their hands as they guided and, in some cases, lifted them onto an awaiting bus that would take them to safety.
The Interior Ministry reported the schoolchildren were being evacuated to sports facilities in nearby Mitry-Mory.
One father, who lives across the street from a school and asked to be identified only as Teddy, described the situation as "very worrying."
"It's like a war," he said. "I don't know how I will explain this to my 5-year-old son."
Two days ago, it was all about Charlie Hebdo, the magazine whose offices came under ruthless attack, with staff members called out and summarily executed.
Now, it's about Cherif Kouachi, 32, and Said Kouachi, 34, the brothers allegedly behind that horrific violence, who set off a massive manhunt after they got away.
Authorities followed a lead Thursday morning from a gas station attendant near Villers-Cotterets, about 40 kilometers (25 miles) from Dammartin-en-Goele, whom the Kouachis reportedly threatened as they stole food and gas. Police think the brothers may have later fled on foot into nearby woodlands.
Northern France's Picardy region is the focal point of the manhunt, with Prime Minister Valls putting it on the same, highest-possible alert level as has been in place since Wednesday in and around Paris.
And police spying down with night vision optics from helicopters say they think they caught a glimpse of them Thursday near Crepy-en-Valois, France -- not far from the reported robbery.
That town and the gas station border on a patch of woods, and on another side of the forest, 30 to 40 police vehicles swarmed out from the town of Longpont.
Squads of officers armed with rifles -- some in helmets and with shields -- canvassed fields and forest.
They didn't find the Kouachi brothers there. Instead, somehow, they're believed to have moved to Dammartin-en-Goele.
Other places, other troubles
More than 80,000 officers deployed across France to try to intercept the brothers and anyone else -- like those behind the Montrouge shooting, which authorities ruled a terror attack -- intent on inflicting harm.
"France is living through a trial, when we see the worst massacre of this kind in the last 50 years," President Francois Hollande said Friday. "It shows when a newspaper is attacked that it's because it's the expression of liberty itself."
As they stand guard against more bloodshed, authorities are working to piece together what's happened already and the backgrounds of those responsible.
Police have detained at least nine people in connection with the Charlie Hebdo investigation, in addition to searching residences in a few towns.
They're also trying to learn more about the brothers they believe carried out the horrific attack.
His older brother, Said, the elder of the Kouachi brothers, has been to Yemen, a French official said. There, he had weapons training with al Qaeda, a U.S. official with access to French intelligence said.
Cherif Kouachi was sentenced to three years in prison for being part of a jihadist recruitment ring in Paris that sent fighters to join the conflict in Iraq.
An ISIS radio broadcast Thursday praised the attackers, calling them "brave jihadists." But the broadcast did not say whether the two had any connection to the militant group.
Bloodshed, satire, values
Charlie Hebdo's staff is as defiant as it was after its former offices were fire-bombed in 2011, the day it was to publish an issue poking fun at Islamic law.
Back then, editor and cartoonist Stephane Charbonnier, "Charb" for short, said it would not slow them down one bit. The magazine continued lampooning world religions, politics and society in its hallmark profane -- at times vulgar -- style.
Some have found their drawings offensive, but they are not uncommon for European comic satire aimed at an adult audience.
Since the attack, Charb was guarded day and night, a journalist who knew him told CNN. Yemen's al Qaeda in the Arabian Peninsula placed him on a list of assassination targets.
He was among those killed Wednesday, along with four other well-known cartoonists known by the pen names Cabu, Wolinski, Honore and Tignous.
Patrick Pelloux, a columnist for the magazine and also a trained paramedic, rushed to the offices when he heard about the shooting.
"I don't know if I'm afraid anymore, because I've seen fear. I was scared for my friends, and they are dead," he told CNN's Anderson Cooper. "I know that they didn't want us to be quiet. They wanted us to continue to fight for these values, cultural pluralism, democracy and secularism, the respect of others. They would be assassinated twice, if we remained silent."
CNN's Jim Sciutto reported from France, Ben Brumfield and Greg Botelho wrote from Atlanta. CNN's Atika Shubert, Laura Smith-Spark, Richard Greene, Fred Pleitgen, Christiane Amanpour, Jim Bittermann and Bryony Jones contributed to this report.