Here are the latest developments in this story:
The missing suspects, Islamist brothers, are reportedly holed up in a small printing business around 12 kilometres (7.5 miles) from Charles de Gaulle international airport.
French security forces swarmed a small industrial town northeast of Paris in an operation to capture the brothers, who are believed to be heavily armed.
Helicopters hovered above the town of Dammartin-en-Goele.
Shots were fired as the brothers stole a Peugeot in the early morning hours.
There are reports of at least one hostage taken.
Thousands of French security forces have mobilized to find Cherif Kouachi, 32, and Said Kouachi, 34, after the attack at the office of satirical magazine Charlie Hebdo magazine in which 12 people were shot dead.
The suspects are described in a nationwide notice as "armed and dangerous".
Charlie Hebdo was apparently attacked by the brothers for repeatedly spoofing the Prophet Muhammad.
Cherif Kouachi, 32, and Said Kouachi, 34, were known to intelligence services.
A third suspect, 18-year-old Mourad Hamyd, surrendered at a police station Wednesday evening after hearing his name linked to the attacks.