The AP file photo shows a warplane outside a hangar in al-Balad airbase, north of Baghdad, Iraq

Baghdad, April 18 (RHC)-- At least five rockets have targeted an Iraqi air base hosting the occupying US soldiers and warplanes following a string of similar attacks on the base during past months.

According to the latest reports, during the Sunday attack, at least two projectiles hit the facilities of an American firm inside al-Balad air base, which provides maintenance to planes, a security source was quoted by AFP as saying.  Three more rockets fell outside the premises of the base.

Two foreign contractors -- also known as mercenaries -- and three Iraqi soldiers were wounded, an unnamed source told AFP.   Another report by Reuters quoted officials as saying that Katyusha rockets were used in the attack.

No group has immediately claimed responsibility for the latest attack on the base, which is located 85 kilometers north of the capital Baghdad, and houses F-16 fighter jets in addition to several maintenance companies employing Iraqi and foreign staff.

The Sunday's assault was the latest in a string of attacks against U.S. positions that were carried out after U.S. President Joe Biden, in February, ordered airstrikes on positions of anti-terror Popular Mobilization Units (PMU) along the Iraqi-Syrian border, where they were fighting remnants of the Takfiri Daesh terrorist group.

The Iraqi counter-terrorism forces pledged retaliation, prompting the U.S. military forces to go on high alert and adopt maximum security measures in anticipation of a response.  The last attack on Balad air base was on April 4th when at least two rockets hit the site.