A still image taken from the French TV channel shows the scene of a hostage taking where police and the suspects exchanged fire in Dammartin-en-Goele, northeast of Paris, January 9, 2015. [Photo/chinadaily.com.cn]

French police on guard at the scene of a hostage taking at an industrial zone in Dammartin-en-Goele, northeast of Paris, January 9, 2015. [Photo by Tuo Yannan/chinadaily.com.cn]

Hostages rushed out

News footage of the Hyper Cacher kosher supermarket in the Vincennes district showed dozens of heavily armed police officersmassed outside of two entrances. The assault began with gunfire and a loud explosion at the door, after which hostages were rushed out.

Reuters photographs taken from long distance showed a man holding an infant and looking distressed being herded into an ambulance by police. Others were carried in on stretchers.

French authorities have mobilised a force of nearly 90,000 since Wednesday's attack on Charlie Hebdo, a weekly that has long courted controversy by mocking Islam and other religions.

The Kouachi brothers were prime suspects in this attack when hooded gunmen shot dead 12 people including some of France's top satirical cartoonists along with two police officers.

Security sources said the French-born brothers of Algerian origin had been under surveillance and had been placed onEuropean and US "no-fly" lists.

The violence raised questions about surveillance of radicals, far-right politics, religion and censorship in a land struggling to integrate part of its five million-strong Muslim community, the largest inn theEuropean Union.

Charlie Hebdo had long courted controversy with satirical attacks on Islam as well as other religions and political leaders. A witness said one of the gunmen in Wednesday's attack was heard to shout: "We have killed Charlie Hebdo! We have avenged the Prophet!"