Two of the alleged gunmen responsible for the worst terrorist attack in France in decades are feared to be heading back towards Paris after reportedly being seen in the north of the country amid a continuing manhunt.

Three gunmen murdered 12 people and wounded at least 11 others on Wednesday morning at the Paris headquarters of _Charlie Hebdo, _a satirical magazine that had previously been threatened for mocking Islam. One of the attackers is in police custody after handing himself in.

According to Le Parisien, two of the heavily armed attackers were seen this morning in Aisne, near Villers-Cotteret in the Picardy region. They reportedly robbed a gas station for fuel and food, and according to the station manager then headed off in the direction of Paris.

Also today, a police woman was killed and a city employee was critically injured in a second shooting on Paris streets, but it is not yet known if the attacks are related.

On Wednesday, three black-hooded men armed with automatic weapons stormed the _Charlie Hebdo _headquartersin the center of the French capital at around 11:30am local time. They went on to kill 10 of the magazine's staff along with two police officers in a methodical and merciless attack that lasted just minutes.

The men then escaped in a black Citroen that was later found abandoned in Paris's 19th arrondissement — setting off a nationwide manhunt that led cops to Reims, a city 90 miles north of Paris. A terror raid was reportedly carried out Wednesday night by police forces at a site in the town, with reports indicating that at least three apartments were also searched in two separate Paris suburbs.

Police have identified the suspected attackers as Said Kouachi 34, and Cherif Kouachi, 32, as well as 18-year-old Hamyd Mourad.

The Paris prosecutor's office confirmed that one of the suspects in the shooting turned himself in. The youngest of the three suspects, Mourad, walked into a police station in the town of Charleville-Mézières, some 142 miles northeast of Paris near the Belgium border, allowing police to take him into custody.

Anonymous sources reportedly told BFM TV News that he turned himself in after seeing his name on social media.

Police in France now appealing for information on the remaining suspects (Kouachi brothers) — David Clinch (@DavidClinchNews)January 8, 2015

Police hunted for the remaining suspects overnight. Reports indicated police conducted several raids across Paris and Reims. Early on Thursday morning the French Prime Minister, Manuel Valls, confirmed that "several arrests" were made overnight in an interview with RTL Radio. French Interior Minister Bernard Cazeneuve added that "seven people" had been arrested in the raids so far.

It also emerged that Cherif Kouachi had previously been convicted of a terror charge in 2008, having helped funnel fighters from France to Iraqi insurgents. He was sentenced to 18 months in prison. Valls said there was "no doubt" the brothers were known to authorities and would have been under surveillance in the past.

Cazeneuve confirmed that one individual had been arrested and one suspect was on the run after the shooting. Police described the suspect as 175 centimeters tall with a shaved head by police, according to reports on France24.

Fusillade au sud de Paris: les deux blessés dans un état critique (source policière) — Agence France-Presse (@afpfr)January 8, 2015

An eyewitness to Wednesday's attack on Charlie Hebdo, who asked to remain anonymous, told VICE News that she arrived in the area as the shooting started and while taking cover heard heavy gunfire lasting for around 10 minutes as well as what sounded like a rocket propelled grenade. Armed police quickly arrived at the scene and exchanged fire with the attackers.

Shortly after the shooting stopped, a man covered in blood exited the building, yelling, "The bodies and the wounded are over there," she added. A 70-year-old woman who was playing with her granddaughters in a nearby park told VICE News that she heard shooting and saw civilians escaping the area on foot and by bicycle.

Security officials confirmed that the attack had been carried out by three gunmen. France 24 cited sources close to the investigation as saying the men had been armed with Kalashnikovs and a rocket launcher.

Police said the men shouted "The Prophet is now avenged" as they carried out the assault and Paris prosecutor, François Molins, said that witnesses reported the attackers had screamed "Allahu Akbar!" ("God is Great"). The same cry can be heard in unverified video footage apparently shot by onlookers. The men handled their weapons with apparent proficiency and operated with military-like precision.

Charlie Hebdo cartoonist Corinne Rey told the French weekly Humanité that the men identified themselves as al Qaeda and spoke perfect French. They entered the building by forcing Rey to open the door.

A video from the street outside captured by a witness showed the men approaching a wounded policeman then shooting him dead at point blank range as he held up his hands and pleaded.

French President François Hollande said the attack was "undoubtedly" an act of terrorism. Visiting the scene shortly after it had been secured, a visibly emotional Hollande spoke of an "especially barbaric" terrorist act, and declared Thursday a national day of mourning. He added that a number of terrorist attacks had been foiled in recent weeks and that as a result, the nationwide terror alert is now on its highest level. Extra security was also added to the offices of media outlets and places of worship in the capital.

Charlie Hebdo's religious satire has drawn the ire of radical Muslims before. Its offices were firebombed in 2011 after it published a caricature of the Prophet Muhammed. On Wednesday morning, it published a cartoon of Islamic State leader Abu Bakr al-Baghdadi, leader of the Islamic State militant group which operates in Iraq and Syria and has called for "lone wolf" attacks on the West.

The magazine was already under police protection as a result of previous threats and one of the two policeman killed had been assigned to protect the newspaper's editor, Stephane Charbonnier — who was killed in the attack — following warnings that he would be targeted, according to France 24. The dead also included cartoonists Jean Cabut, Georges Wolinski, and Bernard Verlhac, as well as writer Bernard Maris.

The attack comes at a time when Islamic extremism is a key security concern across Europe. Lawmakers are particularly concerned that individuals who have joined armed extremist groups to fight in Syria might return home to stage attacks.

Prominent Muslim figures throughout Europe immediately denounced the killings. The Union of Islamic Organizations in France (UOIF) said in a statement: "Charlie Hebdo has just become the target of an appalling attack... The UOIF condemns, in the strongest possible terms, this criminal attack and these horrible murders."

US President Barack Obama pledged to help bring the perpetrators of this "horrific shooting" to justice, adding that France had consistently stood up for "universal values" and "offered the world a timeless example that will endure well beyond the hateful vision of these killers."

US Secretary of State John Kerry said the attackers could never destroy the core values of freedom of expression and freedom of the press, and that the killings would only strengthen the French peoples' resolve to stand up for them. "Today's murders are part of a larger confrontation, not between civilizations, no, but between civilization itself and those who are opposed to a civilized world," Kerry told reporters after a meeting with his Polish counterpart in Washington. "The murderers dared proclaim Charlie Hebdo is dead, but make no mistake, they are wrong."

In the hours following the attack the area surrounding the magazine's offices was silent and heavily locked down with a number of police perimeters and scores of uniform and plain-clothed officers as well as ambulances and fire trucks.

Many local residents were unable to return to their homes and stood around in the winter cold. "It's dramatic, it's really weird that it happened in Paris. I've been here for an hour and I'm so shocked that [I] still haven't moved," David, a 23-year-old local resident whose way home was blocked by a police cordon told VICE News.

He blamed radicalized youth for the attacks. "It happened because of the manipulation of young brains, manipulation of the young, especially those that are somewhat lost," he said to nods from those around him. Most were adamant that the magazine should continue working as it always had for decades. "It is a satirical journal. They made fun of everyone, Jews, Catholics, Chinese," Francoise, 63, told VICE News. "The criticism, the satire is my culture. I was vaccinated on Charlie Hebdo," he said, brandishing a battered copy of the magazine that he produced from his coat. "We are hurt, I didn't know them [the victims] personally, but I'm sad."

He added that France should still strive toward peaceful multiculturalism. "To live together is what we should do. Diversity isn't a flaw." As dusk fell, thousands of people began to gather in Paris's Place de la Republique for an unofficial rally in solidarity with the magazine's staff.

Crowds packed even the entrances to the square, but the gathering remained subdued. Many stood silent holding candles and placards. Occasionally chants of "Freedom of expression!" and "Je suis Charlie" broke out.

Adrian, 23, brandished a sign reading "Charb[bonnier] died free". He told VICE News that he wrote the message because the Charlie Hebdo editor "knew he was threatened and he continued to do what he thought was right."