The gunman holding at least five hostages in a kosher market in eastern Paris has threatened to kill them if police launch an assault on the cornered brothers suspected in the newspaper massacre earlier this week, a police official said.

A shooting and hostage-taking attack is under way at a kosher market on the eastern edge of Paris, France’s anti-terrorism prosecutor said.

France has been rocked by a fresh hostage situation after the hunt for the Charlie Hebdo gunmen developed into a siege.