France and Russia both staged air strikes on Islamic State targets in northern Syria on Tuesday as Paris formally requested European Union assistance in its fight against the group behind last Friday's bloody attacks on the French capital.

French warplanes targeted a command post and a recruitment center for jihadists in the Islamic State stronghold of Raqqa in the second consecutive night of strikes ordered by President Francois Hollande, a military command spokesman told Reuters.

A French government source said Russia hit targets in the same area, a day after Hollande appealed to Washington and Moscow to join in a grand coalition to fight the Islamist group that controls swathes of Syria and Iraq.

In Brussels, Defence Minister Jean-Yves Le Drian invoked the EU's mutual assistance clause for the first time since the 2009 Lisbon Treaty introduced the possibility, saying he expected help with French operations in Syria, Iraq and Africa.