Has Iran Launched Airstrikes Against the Islamic State in Iraq?

Reports that Iran has launched airstrikes against Islamic State (IS) fighters in Iraq have raised questions over Tehran's role in the international military effort, as both Iranian and US officials deny that the two longtime foes are coordinating actions against their common enemy.

Al Jazeera ran footage that appeared to show a McDonnell Douglas F-4 Phantom jet of the kind used by the Iranian air force striking IS targets in Diyala province, eastern Iraq, and US Pentagon Press Secretary Rear Admiral John Kirby subsequently said American officials had no reason to doubt the reports.

"We have no indication that the reports are not true, that Iranian aircraft have conducted airstrikes in the last several days against ISIL targets in eastern Iraq," he told reporters on Tuesday.

However, when questioned, Iranian foreign ministry spokeswoman Marzieh Afkham would not say that the attacks had taken place. "There has been no change to Iran's policy to provide support and advice to Iraqi officials in the fight against Daesh [IS]," she said, according to AFP. "I do not confirm this information on military cooperation [with Iraq]. We provide military support and advice in the context of international rules."

A senior Iranian official cited by Reuters denied the bombings completely. "Iran has never been involved in any airstrikes against IS targets in Iraq," they said.

The US has been carrying out airstrikes on IS targets in Iraq since August 8, and it has been widely suggested by analysts that if Iran has also conducted attacks it would require a degree of coordination with the international coalition.

According to David Cenciotti, a military aviation expert and editor of The Aviationist, it's unlikely that Iranian aircraft would fly inside Iraq without at least informing the US-led coalition of their presence and intentions.

"Although it is theoretically possible for Iranian planes to fly inside Iraq without any coordination with other air forces operating in the same airspace, it would be suicidal," Cenciotti told Business Insider. "For proper deconfliction of tactical assets, prior coordination and air space management and control are required. There are several aircraft performing Airspace Control and Airborne Early Warning over Syria and Iraq: no plane could fly undetected in the area."

However Kirby said that there had been no cooperation between the two countries while operating in the same airspace. Iranian Armed Forces Deputy Chief of Staff Brig-Gen Massoud Jazayeri did not specifically comment on whether the country's jets might have carried out strikes, but did deny any military collaboration with Washington, telling Iran's Fars news agency that such reports would be "totally untrue."

Iran reportedly delivered Sukhoi Su-25 attack jets to the Iraqi military in July. Russia previously delivered a number of the aircraft to Baghdad, but according to the International Institute for Strategic Studies (IISS) a number seen in Iraq were Iranian, based on their serial numbers and also their camouflage scheme — identical to the one currently, and uniquely, applied to Iranian Su-25s. Key operator markings, such as Iranian roundels, had also been crudely painted over, IISS said. Many have speculated that these planes are also being flown by Iranian pilots.

Reports of the Iranian strikes came as US Secretary of State John Kerry said coalition efforts were seriously damaging IS's ability to operate, but warned that it could take years to defeat the group.

"Our commitment will be measured most likely in years, but our efforts are already having a significant impact," Kerry said while speaking in Brussels during the first high level meeting of the more than 60 countries involved in the coalition. "The roughly 1,000 coalition air missions that we have flown have reduced Daesh's [IS] leadership and inflicted damage on its logistical and operational capabilities," he said, adding that the group's advance across Iraq and Syria had now been halted and in some cases reversed.

President Barack Obama assembled a broad anti-IS alliance earlier this year, but American officials said it would be inappropriate for Iran to join. Whether or not the Iranian strikes took place, however, IS has already made unexpected bedfellows of Washington and Tehran.

Both have provided weapons to Iraq's central government and peshmerga forces in iraqi Kurdistan, and both have advisers on the ground.

The US is authorized to deploy up to 3,100 troops in Iraq and a number of sources on the ground have previously told VICE News that there is also a sizeable Iranian military presence in a number of different parts of the country, from bases near the Islamic State-held city of Tikrit, to Kurdish Erbil and Jalawla and Samarra, north of Baghdad.

Most said the Iranians were serving in advisory roles. However, some are apparently serving in active combat, and IRNA, Iran's official state media outlet, has previously reported that an Iranian pilot was killed while "defending" Shiite holy sites in Samarra.

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