A minute's silence was observed at the Ligue 1 match between Lille and Evian on Wednesday followed by an emotional rendition of La Marseillaise, the French national anthem, in honour of the 12 victims of the Charlie Hebdo attack.

France's professional league said that a minute's silence will also be held at all Ligue 1 and Ligue 2 matches this weekend. Players of both teams on Wednesday wore black armbands.

"Following the horror of the gun attack at Charlie Hebdo, Michel Seydoux (Lille president) and Lille football club express their fright and deep sadness," read a club statement.

Lille midfielder and captain Rio Mavuba tweeted: "Where is the world going? A thought for the victims and their loved ones."

Twelve people, including two policemen, were shot dead by heavily armed gunmen at the offices of the satirical weekly magazine Charlie Hebdo in central Paris on Wednesday morning.

Three men are being hunted after they stormed the paper's offices shouting Islamist slogans with witnesses hearing the attackers shout "we have avenged the prophet" and "Allahu akbar" (God is greatest).

Four people remain critically injured and the capital placed under the highest alert status following the attack, the country's deadliest in decades.