It was the second attack against US forces in Iraq since early February when Iranian-backed groups in Iraq stopped their attacks against US troops.
Bahrain, home to the US Navy Fifth Fleet, has long blamed Tehran for stirring up its own majority Shi'ite Muslim population against the country's Sunni monarchy.
Two different explosive devices were detonated at the checkpoint on Saturday evening, according to the Iraqi Security Media Cell.
It was not the love of Tel Aviv that the United Arab Emirates, Bahrain, Jordan, Egypt, Morocco, and -- unofficially -- Saudi Arabia together with Israel, but rather a fear and hatred of Tehran.
A roadside bomb placed near a police car in southeastern Iran failed to go off, killing one militant and sending the second militant fleeing.
Iraq's sectarian parliamentary system breeds instability and creates incentives to persecute people.
Saudi leaders no doubt believe that restoring diplomatic relations is a useful political ploy, but surely appreciate that the deal is superficial.
Three major Sunni Muslim provinces in Iraq are witnessing great prosperity after their liberation from ISIS in 2017, with building projects underway.
Protests have taken place in Zahedan every Friday for the past four months, despite a deadly crackdown by security forces.