WASHINGTON (Reuters) -- The White House said on Monday it has seen "some intensification" of Russian air strikes against Islamic State group in Syria during the past several weeks.

White House deputy national security adviser Ben Rhodes told reporters that Russia previously had infrequently targeted Islamic State in its campaign in Syria.

Maps of Russian airstrikes prepared by the British government and seen by Reuters show that, at least as of a week ago, there has been little change in Moscow’s practice of targeting non-Islamic State areas in Syria with its airstrikes.

The vast majority of Russian airstrikes have targeted areas contested by U.S.-backed rebels fighting Syrian President Bashar Assad, while relatively few have hit Islamic State territory in Raqqah, Dayr az Zawr, and east of Aleppo, according to the maps.

(Reporting by Jeff Mason in Paris and Warren Strobel in Washington, writing by Julia Edwards; Editing by Doina Chiacu and Steve Orlofsky)