Police stand guard in Dammartin-en-Goele, north-east of Paris, where two brothers suspected of Charlie Hebdo attack held one person hostage as police cornered the gunmen, on Jan. 9, 2015. French security force launched assault against Kouachi brothers, killed the two suspects of Charlie Hebdo attack. (Xinhua/Chen Xiaowei)

Media vehicles gather in Dammartin-en-Goele, north-east of Paris, where two brothers suspected of Charlie Hebdo attack held one person hostage as police cornered the gunmen, on Jan. 9, 2015. French security force launched assault against Kouachi brothers, killed the two suspects of Charlie Hebdo attack. (Xinhua/Chen Xiaowei)

Police change shifts in Dammartin-en-Goele, north-east of Paris, where two brothers suspected of Charlie Hebdo attack held one person hostage as police cornered the gunmen, on Jan. 9, 2015. French security force launched assault against Kouachi brothers, killed the two suspects of Charlie Hebdo attack. (Xinhua/Chen Xiaowei)

A policeman checks a car in Dammartin-en-Goele, north-east of Paris, where two brothers suspected of Charlie Hebdo attack held one person hostage as police cornered the gunmen, on Jan. 9, 2015. French security force launched assault against Kouachi brothers, killed the two suspects of Charlie Hebdo attack. (Xinhua/Chen Xiaowei)

Police control traffic in Dammartin-en-Goele, north-east of Paris, where two brothers suspected of Charlie Hebdo attack held one person hostage as police cornered the gunmen, on Jan. 9, 2015. French security force launched assault against Kouachi brothers, killed the two suspects of Charlie Hebdo attack. (Xinhua/Chen Xiaowei)

Jounalists interview police officials in Dammartin-en-Goele, north-east of Paris, where two brothers suspected of Charlie Hebdo attack held one person hostage as police cornered the gunmen, on Jan. 9, 2015. French security force launched assault against Kouachi brothers, killed the two suspects of Charlie Hebdo attack. (Xinhua/Chen Xiaowei)

Local children are evacuated in Dammartin-en-Goele, north-east of Paris, where two brothers suspected of Charlie Hebdo attack held one person hostage as police cornered the gunmen, on Jan. 9, 2015. French security force launched assault against Kouachi brothers, killed the two suspects of Charlie Hebdo attack. (Xinhua/Chen Xiaowei)

A policeman watches in distance in Dammartin-en-Goele, north-east of Paris, where two brothers suspected of Charlie Hebdo attack held one person hostage as police cornered the gunmen, on Jan. 9, 2015. French security force launched assault against Kouachi brothers, killed the two suspects of Charlie Hebdo attack. (Xinhua/Chen Xiaowei)

Local children are evacuated in Dammartin-en-Goele, north-east of Paris, where two brothers suspected of Charlie Hebdo attack held one person hostage as police cornered the gunmen, on Jan. 9, 2015. French security force launched assault against Kouachi brothers, killed the two suspects of Charlie Hebdo attack. (Xinhua/Chen Xiaowei)

Police stand guard in Dammartin-en-Goele, north-east of Paris, where two brothers suspected of Charlie Hebdo attack held one person hostage as police cornered the gunmen, on Jan. 9, 2015. French security force launched assault against Kouachi brothers, killed the two suspects of Charlie Hebdo attack. (Xinhua/Chen Xiaowei)

A police dog handled by a policeman checks a car in Dammartin-en-Goele, north-east of Paris, where two brothers suspected of Charlie Hebdo attack held one person hostage as police cornered the gunmen, on Jan. 9, 2015. French security force launched assault against Kouachi brothers, killed the two suspects of Charlie Hebdo attack. (Xinhua/Chen Xiaowei)