Two brothers suspected of having gunned down 12 people in an attack on satirical magazine Charlie Hebdo were spotted on Thursday morning and are armed, sources close to the manhunt said.
The manager of a petrol station near Villers-Cotteret in the northern Aisne region "recognised the two men suspected of having participated in the attack against Charlie Hebdo", the source said.
An explosion occurred early Thursday at a kebab shop near a mosque in the eastern French town of Villefranche-sur-Saone, officials said, but left no casualties.
"It is a criminal act," a local official told AFP, adding that a police investigation has been opened. No link was suggested with the deadly attack on the Paris magazine a day earlier.
AFP also reported that Muslims places of worship in two French towns were fired upon overnight, leaving no casualties, prosecutors said on Thursday.
The incident comes on a day when a stunned and outraged France was in mourning, as security forces desperately hunted two brothers suspected of gunning down 12 people in a terror attack on a satirical weekly.
The massacre, the country's bloodiest attack in half a century, triggered poignant and spontaneous demonstrations of solidarity around the world.
Shocked people from Moscow to Washington rallied in their tens of thousands under the banner "I am Charlie", in support of press freedom and the controversial Charlie Hebdo magazine that has repeatedly lampooned the Prophet Mohammed.
Nearly 24 hours after the brazen daylight assault, the masked, black-clad gunmen -- who shouted "Allahu akbar" ("God is greatest") while killing some of France's most outspoken journalists as well as two policemen -- were still on the loose.
Interior minister Bernard Cazeneuve said seven people had been detained in the hunt for the brothers, and a judicial source who refused to be named added these were men and women close to the suspects.
Prime Minister Manuel Valls, meanwhile, told French radio the two suspects were known to intelligence services and were "no doubt" being followed before Wednesday's attack.
Police hunted on Thursday for the two heavily armed men, one with possible links to al Qaeda . France began a day of national mourning for what its president called "an act of exceptional barbarism."
One of the suspects, Cherif Kouachi, had a history of funneling jihadi fighters to Iraq and a terrorism conviction from 2008. He and his brother, Said, should be considered "armed and dangerous," French police said in a bulletin early Thursday, appealing for witnesses after a fruitless search in the city of Reims, in French Champagne country.
A third man, Mourad Hamyd, 18, surrendered at a police station in a small town in the eastern region after learning his name was linked to the attacks in the news and social media, said Paris prosecutor's spokeswoman Agnes Thibault-Lecuivre. She did not specify his relationship to the Kouachi brothers.
France raised its terror alert system to the maximum and bolstered security with more than 800 extra soldiers to guard media offices, places of worship, transport and other sensitive areas. A nationwide minute of silence was planned for noon.
Fears had been running high in Europe that jihadis trained in warfare abroad would stage attacks at home. The French suspect in a deadly attack on a Jewish museum in Belgium had returned from fighting with extremists in Syria; and the man who rampaged in the south of France in 2012, killing three soldiers and four people at a Jewish school in Toulouse, received paramilitary training in Pakistan.
One witness to Wednesday's attack said the gunmen were so methodical he at first mistook them for an elite anti-terrorism squad. Then they fired on a police officer.
The masked, black-clad men with assault rifles stormed the offices near Paris' Bastille monument in the Wednesday noontime attack on the publication, which had long drawn condemnation and threats - it was firebombed in 2011 - for its depictions of Islam, although it also satirized other religions and political figures.
The staff was in an editorial meeting and the gunmen headed straight for the paper's editor, Stephane Charbonnier, widely known by his pen name Charb, killing him and his police bodyguard first, said Christophe Crepin, a police union spokesman.
They spoke in fluent, unaccented French as they called out the names of specific employees.
Eight journalists, two police officers, a maintenance worker and a visitor were killed, said prosecutor Francois Molins. He said 11 people were wounded, four of them seriously.
Two gunmen strolled out to a black car waiting below, one of them calmly shooting a wounded police officer in the head as he writhed on the ground, according to video and a man who watched in fear from his home across the street.
"They knew exactly what they had to do and exactly where to shoot. While one kept watch and checked that the traffic was good for them, the other one delivered the final coup de grace," said the witness, who refused to allow his name to be used because he feared for his safety.
One police official, speaking on condition of anonymity because the investigation was ongoing, said the suspects were linked to a Yemeni terrorist network. Cedric Le Bechec, a witness who encountered the escaping gunmen, quoted the attackers as saying: "You can tell the media that it's al-Qaeda in Yemen."
After fleeing, the attackers collided with another vehicle, then hijacked another car before disappearing in broad daylight, Molins said.
The other dead were identified as cartoonists Georges Wolinski and Berbard Verlhac, better known as Tignous, and Jean Cabut, known as "Cabu." Also killed was Bernard Maris, an economist who was a contributor to the newspaper and was heard regularly on French radio.
One cartoon, released in this week's issue and titled "Still No Attacks in France," had a caricature of a jihadi fighter saying "Just wait - we have until the end of January to present our New Year's wishes." Charb was the artist.
Le Bechec, the witness who encountered the gunmen in another part of Paris, described on his Facebook page seeing two men "get out of a bullet-ridden car with a rocket-launcher in hand, eject an old guy from his car and calmly say hi to the public, saying 'you can tell the media that it's al Qaeda in Yemen.'"
In a somber address to the nation Wednesday night, French President Francois Hollande pledged to hunt down the killers, and pleaded with his compatriots to come together in a time of insecurity and suspicion."Let us unite, and we will win," he said. "Vive la France!"
Thousands of people later jammed Republique Square near the site of the shooting to honor the victims, waving pens and papers reading "Je suis Charlie" - "I am Charlie." Similar rallies were held in London's Trafalgar Square as well as Madrid, Barcelona, Berlin and Brussels.
"This is the darkest day of the history of the French press," said Christophe DeLoire of Reporters Without Borders.
Both al Qaeda and the Islamic State group have repeatedly threatened to attack France, which is conducting airstrikes against extremists in Iraq and fighting Islamic militants in Africa. Charb was specifically threatened in a 2013 edition of the al-Qaeda magazine Inspire, which also included an article titled "France the Imbecile Invader."
Cherif Kouachi, now 32, was sentenced to 18 months in prison after being convicted of terrorism charges in 2008 for helping funnel fighters to Iraq's insurgency. He said he was outraged at the torture of Iraqi inmates at the US prison at Abu Ghraib near Baghdad and "really believed in the idea" of fighting the US-led coalition in Iraq.
A tweet from an al Qaeda representative who communicated Wednesday with The Associated Press said the group was not claiming responsibility for the attack, but called it "inspiring."
The bells will peal
Hollande ordered flags to fly at half-mast for three days in France and was due to convene an emergency cabinet meeting at 8:30 am (0730 GMT).
A minute's silence will be observed across the country at midday, after which the bells of Paris's famous Notre Dame cathedral will sound out across the capital.
"Nothing can divide us, nothing should separate us. Freedom will always be stronger than barbarity," said the president, calling for "national unity."
Even before the attack, France, home to Europe's biggest Muslim population, was on high alert like many countries that have seen citizens leave to fight alongside the radical Islamic State group in Iraq and Syria.
"Several terrorist attacks had been foiled in recent weeks," Hollande said.
'Abominable, never justified'
US President Barack Obama led the global condemnation of what he called a "cowardly, evil" assault. Pope Francis described it as a "horrible attack" saying such violence, "whatever the motivation, is abominable, it is never justified".
Visiting the scene, the imam of the Drancy mosque in the northern suburbs of Paris, Hassen Chalghoumi, called the shooters "barbarians".
"They want terror, they want fear. We must not give in. I hope the French will come out in solidarity and not against the Muslim minority in Europe," he told AFP.
Meanwhile, cartoonists reacted as they know best, composing biting and mocking satirical drawings against what editorialists said was an attack on the very foundations of democracy.Among the cartoons that went viral online was one by Australia's David Pope: a picture of a gunman with a smoking rifle standing over a body, bearing the caption "He drew first".
France's media erupted in fury at the massacre of their colleagues, with the daily Liberation running the headline 'We are all Charlie" -- a line repeated in many other papers and echoed online with the hashtag #JeSuisCharlie.
Business daily Les Echos urged people to face up to "barbarism", publishing the last cartoon written by one of those killed in the attack. "The hooded bastards declared war on France, on our democracy, on our values," the paper said in an editorial.
Charlie Hebdo gained notoriety in February 2006 when it reprinted cartoons of the Prophet that had originally appeared in Danish daily Jyllands-Posten.
Its offices were fire-bombed in November 2011 when it published a cartoon of Mohammed under the title "Sharia Hebdo".
Even being dragged to court under anti-racism laws did not stop the publication, which in September 2012 again drew the Prophet, this time naked.
The attackers on Wednesday shouted "we have avenged the prophet, we have killed Charlie Hebdo", according to prosecutors.
The assault took place on the day the latest edition of Charlie Hebdo was published.
It featured a cartoon of an armed militant noting "Still no attacks in France. Wait! We have until the end of January to send greetings". That was a reference to France's tradition of wishing someone a Happy New Year before January 31.
Editor-in-chief Stephane Charbonnier, known as Charb and who had lived under police guard after receiving death threats, was among those killed, along with the police officer assigned to protect him.
Other victims included Jean Cabut, known across France as Cabu, Georges Wolinski and Bernard Verlhac, better known as Tignous.
(With inputs from Reuters, AFP, AP)