Iran's Supreme Leader says its ballistic missile attack on forces in Iraq was "a slap on the face" for the US, and hinted at further military action.

Ayatollah Ali Khamenei made the stern remarks in front of a packed crowd in Tehran in response to the US's drone strike on Iranian Revolutionary Guard General Qassem Soleimani.

"Last night we slapped them on the face," Khamenei said, as the crowd chanted "death to America" and "death to Israel".

"When it comes to confrontation, military actions of this kind is not enough."

He said what is important is that the presence of the "corrupt president of the US should come to an end" and that the US brought "war and hostility and deception".

"I can say this very clearly that the enemy is America," he said.



Iranian Supreme Leader Ayatollah Ali Khamenei openly weeps as he leads a prayer over the coffin of Gen. Qassem Soleimani. (AP)

The missile attack

Iran launched a ballistic missile attack earlier today targeting two bases in Iraq housing US forces in retaliation for the killing of Soleimani.

Iranian officials stated the attack began at 1.20am (local time), the same time General Soleimani was killed last Friday.

"The fierce revenge by the Revolutionary Guards has begun," Iran's military said in a statement.

One US official told the New York Times that six rockets had landed at the Ain Assad airbase. The airbase is located in Iraq's western Anbar province.



Donald Trump said killing Iran's top general would de-escalate tensions in the Middle East. (AP)

A US official said there were no initial reports of any US casualties from the attack, but an assessment of the impact of the strikes is underway. Iraq's joint military command said there were no casualties among Iraqi military forces.

It was first used by American forces after the 2003 US-led invasion that toppled dictator Saddam Hussein. It later saw American troops stationed there amid the fight against the Islamic State group in Iraq and Syria.

Trump's response

US President Donald Trump responded to the Iranian rocket attack with a single tweet.

"All is well!," he wrote.

"Missiles launched from Iran at two military bases located in Iraq. Assessment of casualties and damages taking place now. So far, so good!

"We have the most powerful and well equipped military anywhere in the world, by far! I will be making a statement tomorrow morning."



This aerial photo taken from a helicopter shows Ain al-Asad air base in the western Anbar desert, Iraq, Sunday, Dec. 29, 2019. (Nasser Nasser/AP)

Australia's response

All Australian personnel in Iraq are safe following the Iranian rocket attack.

Prime Minister Scott Morrison confirmed that diplomatic and Defence Force personnel in Iraq are all safe and accounted for in the attack.

The two bases targeted are Ain Assad in central Iraq, and Irbil in Kurdistan.

It is not known if any Australian personnel were at either base.

But Ain Assad was secured by the Australian SAS during the invasion of Iraq in 2003 before being handed over to US forces.

There are currently about 450 Australian defence personnel in Iraq.



In this December 26, 2018, file photo, President Donald Trump speaks to members of the military at a hangar rally at Ain al-Asad air base, Iraq. (AP Photo/Andrew Harnik)

No fly zone

Qantas will avoid flying over Iran and Iraq airspace until further notice following the a series of ballistic missile attacks. This affects two of the Australian airline's flights.

Singapore Airlines said in a statement today its flights into and out of Europe have been diverted from Iranian airspace, adding that it is "monitoring the situation closely and will make the appropriate adjustments to our routes if necessary."

Taiwan's EVA Air said the carrier's European flights began avoiding flying over Iran early this morning Taiwan time to ensure safety.



Iranian forces attacked Ain Assad Air Base in central Iraq and Erbil Air Base in Iraqi Kurdistan. (Nine)

Malaysia Airlines said in a statement that due to recent events, it "will be avoiding the conflict airspace of Iran".

The US Federal Aviation Administration has banned American civilian planes from flying over Iraq, Iran, and the waters of the Persian Gulf and the Gulf of Oman.

The ruling would affect flights in and out of the travel hubs of Dubai, Qatar and Abu Dhabi.

"The FAA will continue closely monitoring events in the Middle East," the administration said in a statement.

The "potential for miscalculation or mis-identification" could put passenger planes at risk of being shot down as tensions heighten in the region.



Iran has launched a missile attack on a military base hosting US troops in Iraq. (Fars News)

Who is Qassem Soleimani?

General Qassem Soleimani was assassinated by US forces outside Baghdad airport last week.

The general was a beloved figure in Iran, a close friend of the Ayatollah and one of the most influential men in the Middle East.

But he was also considered a war criminal by the United States, heading a paramilitary force in Iran designated as a terrorist group.

As the head of the Quds Force of Iran's paramilitary Revolutionary Guard, General Soleimani led all of its expeditionary forces.

He was viewed as the second most powerful man in Iran, and a possible presidential candidate.

Quds Force members have deployed into Syria's long war to support President Bashar Assad, as well as into Iraq in the wake of the 2003 US invasion that toppled dictator Saddam Hussein, a long time foe of Tehran.



Soleimani rose to prominence by advising forces fighting Islamic State in Iraq and in Syria on behalf of the embattled Assad.

Millions turned out in Iran to mourn him this week.

A funeral procession in his home town turned into a stampede overnight, leading to the deaths of dozens of mourners.

How big is the Iranian Army?

Iran is a major military power in the Middle East, and ranked the 14th most powerful armed forces in the world by Global Firepower's 2019 Military Strength Ranking.

Its forces total about 523,000 active personnel.



Iran's elite Revolutionary Guards tests missiles during maneuvers in a central desert area of Iran. (AAP)

Iran's formidable Islamic Revolutionary Guard Corps, more widely known as the Revolutionary Guard, is the nation's elite force, comprised of 125,000 men.

The Iranian military has an arsenal of short, medium and intermediate range ballistic missiles capable of hitting Israel, Gulf Arab states, US military bases in the region and parts of Europe.

Any conflict would certainly see Iranian forces attempting to block and choke the Strait of Hormuz between the Persian Gulf and the Gulf of Oman, where one-fifth of the world's oil passes through.



Members of the Iran's Revolutionary Guard march during an annual military parade at the mausoleum of Ayatollah Khomeini, outside Tehran, Iran. (AP)

Iran attacks: What we know

More than a dozen Iranian rockets have been launched at two air bases in Iraq.

The attack was in retaliation for the US assassination of high-ranking Iranian general Qassem Soleimani on Friday.

No Australian personnel were injured in the attack.

US President Donald Trump has not made a statement or confirmed any US casualties, but tweeted "All is well!" hours after the missile strike.

US civilian planes have been banned from flying over Iraq, Iran, the Persian Gulf and the Gulf of Oman.