Russia used Iran on Tuesday for the first time as a base from which to launch air strikes against Syrian militants, widening its air campaign in Syria and deepening its involvement in the Middle East.
In a move underscoring Moscow's increasingly close ties with Tehran, long-range Russian Tupolev-22M3 bombers and Sukhoi-34 fighter bombers used Iran's Hamadan air base to strike a range of targets in Syria.
It was the first time Russia has used the territory of another nation, apart from Syria itself, to launch such strikes since the Kremlin launched a bombing campaign to support Syrian President Bashar al-Assad in September last year.
The Iranian deployment will boost Russia's image as a central player in the Middle East and allow the Russian air force to cut flight times and increase bombing payloads.
The head of Iran's National Security Council was quoted by state news agency IRNA as saying Tehran and Moscow were now sharing facilities.
Both countries back Assad. Russia, after a delay, has supplied Iran with its S-300 missile air defense system, evidence of a growing partnership that has helped turn the tide in Syria's civil war and is testing U.S. influence in the Middle East.