After a car chase on France’s RN2 main road, the men took refuge in a printworks on an industrial estate at Dammartin-en-Goële, where they took at least one employee hostage, reports said.
The interior ministry confirmed on Friday morning that, thanks to sevral witnesses, it was "almost certain" that the two individuals inside the building were Chérif and Saïd Kouachi, who have been sought by police since they allegedly murdered 12 people in the attack on the offices of the satirical paper on Wednesday.
Residents and local workers have been ordered to stay indoors.
Gendarmes and police from the elite GIGN and Raid units were rushed to the scene to start negotatiations.
A large police deployment was launched north-east of Paris after the Kouachi borthers fled the capital, ditching at least one car and holding up a service station on the way.