DAMMARTIN GOELE: The two main suspects in the Charlie Hebdo killings were sighted on Friday in the northern French town of Dammartin-en-Goele where at least one person had been taken hostage, a police source said.

Interior Minister Bernard Cazeneuve separately confirmed a police operation was underway in the town, some 40 km (25 miles) from the site of where police had been hunting the two suspects on Thursday.

Hooded gunmen stormed the Paris offices of a weekly satirical magazine on Wednesday, killing at least 12 people, including two police officers in the worst militant attack on French soil in recent decades.

France Info radio said police had confirmed 10 injured. Police informed Reuters that of the 10 wounded, five were injured critically.

Read: Two suspects in Paris magazine shooting spotted in north France

Charlie Hebdo (Charlie Weekly) is well known for courting controversy with satirical attacks on political and religious leaders.

Victims included four prominent cartoonists, among them the editor-in-chief, Stephane Charbonnier, who had lived under police protection for years after receiving death threats.

The chief editor was holding a morning meeting when the assailants armed with Kalashnikovs burst in and opened fire. The three other cartoonists who died were Jean Cabut, Georges Wolinski and Bernard Verlhac.

French Police, earlier on Thursday, identified three men, including two brothers, as suspects in the attack at the offices of weekly satirical newspaper Charlie Hebdo, as security officers fanned out around the Paris region in a manhunt.

Also read: 12 dead in shooting at Paris offices of satirical magazine

Two police officials named the three suspects as Frenchmen Said Kouachi and Cherif Kouachi, who are brothers and in their early 30s, as well as 18-year-old Hamyd Mourad, whose nationality wasn't immediately clear.

The officials spoke on condition of anonymity because they weren't authorised to publicly discuss the sensitive and ongoing investigation.

Cherif Kouachi was convicted in 2008 of terrorism charges for helping funnel fighters to Iraq's insurgency, and sentenced to 18 months in prison.

During his 2008 trial, he told the court he was motivated by his outrage at television images of torture of Iraqi inmates at the US prison at Abu Ghraib.