The senior commander belonged to Kata’ib Hezbollah.

"U.S. Central Command (CENTCOM) forces conducted a unilateral strike in Iraq in response to the attacks on U.S. service members, killing a Kata’ib Hezbollah commander responsible for directly planning and participating in attacks on U.S. forces in the region," Centcom said in a statement.

The Central Command said no casualty or collateral damage has been reported so far.

"The United States will continue to take necessary action to protect our people. We will not hesitate to hold responsible all those who threaten our forces’ safety," the statement said.

Kataib Hezbollah group has claimed responsibility for several attacks on U.S. forces in Iraq.

Last week, the group said it would no longer target US troops.

A source told Xinhua news agency that one man killed in the car was identified as Abu Baqir al-Saadi, a commander of Kataib Hezbollah, an Iran-backed armed group in Iraq that has links to Hashd Shaabi Forces, or the Popular Mobilization Forces.

After the attack, Iraqi security forces intensified security measures around the heavily fortified Green Zone, which houses some of the main government institutions and foreign diplomatic missions, including the U.S. embassy, in anticipation of any security breaches, according to the source.

The Iraqi Joint Operations Command said in a statement via its affiliated media outlet Security Media Cell that a bombardment targeted a civilian car at 9:35 p.m. local time (1835 GMT) in the al-Mashtal neighbourhood, killing those aboard, reported Xinhua.