Mortar bombs hit Iraq base hosting US troops: Military sources

Seven mortar bombs fell on Sunday inside Iraq's Balad air base, which houses US forces, and four Iraqi soldiers were wounded in the attack, two military sources told Reuters.

The military sources said the mortar bombs fell in the base's runway inside the base, which is 80km north of Baghdad. Balad is the main airbase for Iraq's F-16s, which it bought from the US to upgrade its air capacities. 

The base had held a small US Air Force contingent as well as American contractors, but a majority had been evacuated following tensions between the US and Iran over the past two weeks, military sources told AFP.

"About 90 percent of the US advisers, and employees of Sallyport and Lockheed Martin who are specialised in aircraft maintenance, have withdrawn to Taji and Erbil after threats," one of the sources said. "There are no more than 15 US soldiers and a single plane at al-Balad," the source added. 

Later on Sunday, US Secretary of State Mike Pompeo said he was "outraged" by another attack on an Iraqi airbase where US forces have been stationed.

"Outraged by reports of another rocket attack on an Iraqi airbase," Pompeo tweeted. "These continued violations of Iraq's sovereignty by groups not loyal to the Iraqi government must end."

There was no immediate claim of responsibility for Sunday's rocket attacks, though the US has previously blamed such attacks on Iran-backed groups in Iraq.

Military bases hosting US troops have been subject to volleys of rocket and mortar attacks in recent months that have mostly wounded Iraqi forces, but also killed one American contractor last month.  

That death set off a series of dramatic developments, with the US carrying out strikes against a pro-Iran paramilitary group in Iraq as well as on a convoy carrying top Iranian and Iraqi commanders outside Baghdad airport - killing leading Iranian commander Qassem Soleimani and Abu Mahdi al-Muhandis, the deputy head of Iran-backed Iraqi militia Hashd al-Shaabi.

Pro-Iran factions in Iraq have vowed revenge for those raids, even as Iran said it had already responded in "proportion" by striking another western air base where US soldiers are located.

Rocket attacks against Baghdad's high-security Green Zone, where the US and other embassies are based alongside international troops, are still taking place.