ISTANBUL — Russian bombers flying from an Iranian air base struck rebel targets across Syria on Tuesday, Russian and Iranian officials said, dramatically underscoring the two countries’ growing military ties and highlighting Russia’s ambitions for greater influence in a turbulent Middle East.

The long-range Tu-22 bombers took off from a base near Hamadan in western Iran and launched raids in Syria’s Aleppo, Deir al-Zour and Idlib provinces, the Russian Defense Ministry said in a statement Tuesday.

Both countries are staunch allies of Syrian President Bashar Assad, and the flights marked the first time Russia has launched strikes from Iranian territory.

Iran has long banned foreign militaries from establishing bases on its soil. But the raids on Tuesday appeared to signal a budding alliance that would expand Russia’s military footprint in the region.

Iran and Russia “enjoy strategic cooperation in the fight against terrorism in Syria, and share their facilities and capacities to this end,” Iran’s National Security Council chief, Ali Samkhani, said Tuesday, according to the state-run Islamic Republic News Agency.

Shiite-led Iran has sent thousands of troops and fighters, including members of its Revolutionary Guard Corps, to Syria to bolster Assad – who is from the minority Alawite sect – against largely Sunni rebels. For Tehran, losing a longtime ally to a majority-Sunni uprising would undermine its own influence in the region.

Iranian proxies such as Lebanon’s Hezbollah and an array of Shiite Iraqi militias have also fought for the Syrian regime. And last year, Russia intervened as well, committing tanks, artillery and combat aircraft to the fight. It also built a new air base in Latakia province in the Alawite heartland.

But until now, Russia’s long-range bombers, which require longer airstrips, had to be launched from Russian territory more than 1,200 miles away. Now, those same bombers need to fly only about 400 miles from Iran to Syria, Iran’s Fars News Agency reported Tuesday. The shorter distance will allow Russia to intensify its air campaign against rebel-held areas.

Both government troops and opposition fighters are now locked in a battle for the strategic Syrian city of Aleppo, where residents face a growing humanitarian crisis. Russia has carried out strikes in support of government troops there, activists say.

Russia’s Defense Ministry said Tuesday that its long-range bombers struck targets linked to the Islamic State and Jabhat Fatah al-Sham, a group that formally split from al-Qaida last month and changed its name from Jabhat al-Nusra. The strikes destroyed five major ammunition depots, training camps and three command posts, the ministry said.