At least two gunmen have attacked the Paris office of French satirical magazine Charlie Hebdo, killing a number of people, BBC News reports citing French media.

Witnesses spoke of sustained gunfire at the office as the attackers opened fire with Kalashnikov assault rifles.

The satirical weekly has courted controversy in the past with its depiction of news and current affairs.

Its latest tweet was a cartoon of the Islamic State militant group leader, Abu Bakr al-Baghdadi.