Two military convoys for the US-led coalition in Iraq came under fire, security officials confirmed.
The explosive device exploded as a coalition convoy passed by on the outskirts of Baghdad.
However, no injuries or damage were reported during the incident.
Second Attack on the Same Day
Meanwhile, another bomb explosion targeted a coalition convoy in the central Babel province.
Minor damage was reported to a vehicle in convoy.
Neither Iraqi nor US official sources have commented on the attacks so far.
The US forces had frequently come under fire in Iraq.
Washington usually accuses Iran-backed Iraqi groups of being behind such attacks.
However, Tehran has strongly denied the US allegations.
US to Withdraw from Iraq
US President Joe Biden has earlier declared that US forces will end their combat mission in Iraq by this year.
However, he pointed out that the US troops will continue to train and advise the Iraqi military.
The announcement came after Biden held talks with Iraqi Prime Minister Mustafa al-Kadhimi at the White House last month.
There are currently 2,500 US troops in Iraq helping local forces counter what remains of the Islamic State group.
The numbers of US troops are likely to stay the same, but the move is being seen to help the Iraqi PM.
The announcement marks the end of another war that began under former President George W Bush.
The US presence in Iraq has become a major issue since top Iranian general Qasem Soleimani was killed in a US drone strike in Baghdad last year.
This year, the US troops would also leave Afghanistan after two decades of deployment.
The US military prepares its withdrawal from Afghanistan by September 2021, a deadline set by US President Joe Biden to end America’s longest war.
Britain and Germany also declared a decision to withdraw troops from the country.