Paris on Alert as Terrorists Attack on Satire Magazine Charlie Hebdo: Live Blog

— -- Three masked gunmen are on the loose in Paris after reportedly opening fire inside the offices of a famed French satirical magazine.

The attack left 12 dead and at least three others seriously injured.

The gunmen, who have not been identified but were heard screaming "Allahu Akbar" outside the offices in footage obtained by witnesses, were able to escape the scene by car.

All of Paris is on extreme alert and the city's terror warning has been raised to the highest level, with President Francois Hollande revealing that there had been a number of terror threats against media outlets in recent weeks.

Our liveblog, below, will be updated constantly with the latest news.