Shiite militias in Iraq
Shiite militias in IraqReuters

At least five rockets were launched from Iraq's town of Zummar towards a US military base in northeastern Syria on Sunday, two Iraqi security sources told Reuters.

The two sources and a senior army officer said a rocket launcher fixed on the back of a small truck had been parked in Zummar border town with Syria.

The military official said the truck caught fire with an explosion from unfired rockets at the same time as warplanes were in the sky.

"We can't confirm that the truck was bombed by US warplanes unless we investigate it," said a military official.

Iraqi security forces were deployed in the area and launched a hunt for the perpetrators who fled the area using another vehicle, said a security official who is based in the town of Zummar.

The Iraqi Security Medica Cell, an official body responsible for disseminating security information, said in a statement that Iraqi forces had launched "a wide-ranging search and inspection operation" targeting the perpetrators near the Syrian border, pledging to bring them to justice.

The attacks came one day after a blast at a military base in Iraq early on Saturday killed a member of an Iraqi security force that includes Iran-backed groups.

Sunday’s attack against US forces is the first since early February. In February, the US launched a military strike that killed a commander of the Kataib Hezbollah militia in Iraq.

That strike was in retaliation for a drone attack in Jordan in which three US service members were killed.