Russian war planes are again using Iranian airspace to carry out strikes in neighboring Syria, an Iranian official said Saturday.

Russian jets first used an Iranian air base to launch strikes into Syria back in August last year. At the time, the Russian military said its planes had completed their operations for the time being but left open the possibility of using Hamadan air base again if the need arose.

Iran's Foreign Ministry said back then that Russia had stopped using the base for attacks in Syria, bringing the deployment to an abrupt end, amid criticism from both the United States and some Iranian lawmakers.

Ali Shamkhani, the secretary of Iran's National Security Council - and Tehran's coordinator of political, security and military actions with Russia - on Saturday told the semi-official news agency Fars: "Their (Russian bombers') use Iranian of airspace continues because we have a fully strategic cooperation with Russia."

"In the recent cases, Russian fighter planes have only used Iran's airspace and have not had refueling operations," Shamkhani added.

He told the IRNA news agency, "The use of Iranian airspace by Russian aircraft is made subject to a joint decision, taking into account the need ... to fight terrorism."

Backing Bashar al-Assad

Shamkhani was reportedly commenting on media reports that Russia's Tupolev-22M long-range bombers had used Iranian airspace and a base in the country on their missions in Syria, where both Tehran and Moscow are backing President Bashar al-Assad's government.

It is unclear if the recent missions were linked to Russian airstrikes on Thursday that accidentally killed three Turkish soldiers during an operation against "Islamic State" militants in Syria, according to the Turkish military.

Iran and Russia are cooperating in Syria and provide political, financial and military backing to the regime of President Bashar al-Assad.

The Tehran government has sent military advisers and "volunteer" fighters to support the Syrian military in its fight against rebel and jihadist groups.

bik/tj (Reuters, AFP)