Russia has used Iran as a base from which to launch air strikes against Syrian militants for the first time, widening its air campaign in Syria and deepening its involvement in the Middle East.

Key points: Iran and Russia are the two key backers of the Assad regime

Iran and Russia are the two key backers of the Assad regime This is the first time Russia has publicly stated it used a Middle Eastern base for Syria airstrikes

This is the first time Russia has publicly stated it used a Middle Eastern base for Syria airstrikes The US refuses to confirm Russian claims it is close to joining forces with Russia around Aleppo

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.

It was also thought to be the first time that Iran has allowed a foreign power to use its territory for military operations since the 1979 Islamic revolution.

Conducting bombing raids from Iran will dramatically cut the time it takes Moscow's long-range bombers to reach Syria.

Loading...

Russia's defence ministry said the strikes had targeted Islamic State as well as militants previously known as the Nusra Front in the Aleppo, Idlib and Deir al Zour provinces.

It said its Iranian-based bombers had been escorted by fighter jets based at Russia's Hmeymim air base in Syria's Latakia Province.

"As a result of the strikes five large arms depots were destroyed ... a militant training camp [and] three command and control points," the ministry said in a statement.

It added that a "significant number of militants" had been killed in the strikes, which took place on Tuesday (local time).

The destroyed facilities had all been used to support militants in the Aleppo area, it said.

Fighting for Aleppo has intensified after regime troops seized control of the last supply route into rebel-held areas in mid-July.

The latest raids on two rebel-held districts of the city killed 19 civilians, according to the Syrian Observatory for Human Rights.

Strikes in the Tariq al-Bab and al-Sakhour districts of north-east Aleppo had killed around 20 people, while air raids in a corridor rebels opened this month into opposition-held eastern parts of the city had killed another nine, the observatory said.

Zakaria Malahifi, political officer of an Aleppo-based rebel group, Fastaqim, said he could not confirm if the newly deployed Russian bombers were in use.

But he said air strikes on Aleppo had intensified in recent days.

"It is much heavier," he told Reuters.

"There is no weapon they have not dropped on Aleppo — cluster bombs, phosphorus bombs, and so on."

The Iranian deployment will boost Russia's image as a central player in the Middle East.

The head of Iran's National Security Council was quoted by state news agency IRNA as saying Tehran and Moscow were now sharing facilities to fight against terrorism, calling their cooperation strategic.

Iran and Russia are the two firmest backers of the Assad regime and have opposed international calls for the Syrian leader to step down in a bid to resolve a civil war that has killed more than 290,000 people since it erupted in March 2011.

Reuters/AFP