Two masked gunmen entered the Paris headquarters of satirical French magazine Charlie Hebdo and opened fire with automatic weapons, killing at least 11 people, in what President Francois Hollande called a “terrorist attack.”

Speaking at the scene of the attack, Hollande said the government had raised the alert level in the capital to the highest as police hunt for the gunmen, who escaped after the shooting.

One policeman was also killed in the shooting, which lasted several minutes after the gunmen entered the magazine’s offices and started firing.

At least 10 more people were injured, and Hollande said the death toll could rise.

The offices of the weekly magazine were firebombed in November 2011 after it published a spoof issue that featured the prophet Mohammed as editor. No one was injured in that attack.

An online video allegedly taken from an office across the street from Charlie Hebdo showed two masked gunmen leaving the building, one of them shooting dead a policeman before the two sped away in a small black car. The video was removed from Facebook. It could not be independently verified.

Hollande told journalists that security forces had thwarted several attempts to carry out terrorist attacks over the last few weeks.

“It is a terrorist attack, there is no doubt,” Hollande told journalists in central Paris, vowing to find and prosecute the assailants.

The government will also beef up security at department stores, media outlets, places of worship and public transport.

British Prime Minister David Cameron condemned the attack, saying: “The murders in Paris are sickening. We stand with the French people in the fight against terror and defending the freedom of the press.” SAPA