Paris – (NBC) Masked gunmen armed with AK-47s and shouting “Allahu Akbar” stormed the offices of a French satirical news magazine Wednesday in a terror attack that left 12 people dead, including the editor and two police officers.

The suspects shot dead one of the officers on the street as they fled — escaping first in a black Citroen that they abandoned after a crash, and then in a sedan they carjacked from a bystander.

There was no verified claim of responsibility or motive for the ambush, but the target, a weekly publication called Charlie Hebdo, has published cartoons of the Muslim Prophet Muhammad and was firebombed three years ago.

France declared Thursday a national day of mourning, raised its terror threat level and stepped up security for media organizations, large stores and places of worship, and launched a manhunt for the killers with the assistance of the FBI.

“We will find the people who did this,” French President Francois Hollande vowed. He later called for national unity.

“Freedom is always bigger than barbarism,” he said. “Vive la France.”