French police have released three of the 12 suspects arrested in an anti-terror sweep following the attacks in Paris by Islamic extremists that killed 17 people and put Europe on high alert.

One suspect sought in the deadly shooting at a French satirical paper has turned himself in, as police hunt for two heavily armed men with possible links to al-Qaida.

President Barack Obama is offering help to French officials to pursue terrorists responsible for what he is calling a “horrific shooting” at a satirical weekly newspaper.

A French magazine ridiculed the Prophet Mohammed by portraying him naked in cartoons, threatening to fuel the anger of Muslims around the world who are already incensed by a film depiction of him as a womanising buffoon.