Thousands of Russians have been fighting in Syria in anti-government ranks, Russian Prime Minister Dmitry Medvedev said in an interview published on Saturday, issuing a warning of possible attacks by them on their return home.

Last year, Moscow launched an air campaign to hit the targets of militants who have waged a war against Syrian President Bashar Assad. There are also numerous jihadis from Russia who filled the ranks of anti-government forces.

"You probably know that thousands of Russian citizens and individuals from other post-Soviet republics are fighting in Syria," Medvedev told Channel 2 Israel ahead of a visit to Israel next week, according to the interview transcript.