Iran has launched a ballistic missile attack on two bases in Iraq housing US troops.
It comes after days of speculation about how Iran would respond to the killing of the country's top general.
More than a dozen ballistic missiles hit two airbases in Irbil and Al Asad in Iraq.
An assessment of the impact of the strikes is now underway, but there were no initial reports of any US or Iraqi casualties.
It's seen as an Iranian retaliation for the killing of Qasem Soleimani in a drone strike in Baghdad last Friday.
Iran's Foreign Minister tweeted that they don't seek escalation or war, but they will defend themselves against any aggression.
US President Donald Trump meanwhile has tweeted to say "all is well."
All is well! Missiles launched from Iran at two military bases located in Iraq. Assessment of casualties & 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.
— Donald J. Trump (@realDonaldTrump) January 8, 2020
In a statement after the attacks, the Iranian Revolutionary Guard Corps said:
"We warn the Great Satan, the bloodthirsty and arrogant regime of the US, that any new wicked act or further aggression will bring about more painful and crushing responses."