A street sweeper was critically injured in the shooting, which is now being treated as a "terrorist act" by the French authorities.

Sky's Crime Correspondent Martin Brunt said police with heavy armour were seen in Porte de Chatillon shortly afterwards and TV news crews were being pushed back from the area, which was sealed off with tape.

Meanwhile, officers are still hunting for suspects in the deadly gun attack on the offices of satirical magazine Charlie Hebdo.

[Police officer killed in second terror attack, Sky News, January 8, 2015]