France has fired its first airstrikes in Syria as it expands military operations against Islamic State extremists.

President Francois Hollande's office announced Sunday that "France has hit Syria" based on information from French reconnaissance flights sent earlier this month. He didn't provide any further details.

France has been firing airstrikes on IS extremists in Iraq as part of the U.S.-led coalition since last year, but had resisted airstrikes in Syria because it didn't want to strengthen President Bashar Assad. Hollande announced a change in strategy earlier this month because of growing concern about the Syrian refugee crisis.

The president's office argued Sunday that it was a question of national defense, as France has been attacked and threatened by extremists claiming ties to IS.