BAGHDAD — An explosion near the Jraischan crossing at the Iraqi-Kuwaiti border on Monday evening targeted a convoy carrying equipment for US forces, Iraqi security forces said.

It was not immediately clear if there were any US troops in the convoy or if anyone had been injured in the explosion, which went off just before 9 p.m. Baghdad time (1800 GMT).

Vehicles are regularly loaded with military equipment at the crossing, the sources said, and the cargo is usually loaded or unloaded before entering or exiting Iraq.

Foreign companies are contracted by US forces to provide security in the area, the Iraqi security sources said.

A security source had earlier said that the explosion was caused by an Iraqi Shia militia targeting a US military base near the crossing by smuggling in an explosive device, and that some staff on the base had been injured, but this was later contradicted by other security sources who said a convoy was attacked, not a base.

“We are currently looking into this matter,” said a spokesperson for the US Embassy in Kuwait.

A little known Iraqi Shiite militia group by the name of Ashab Al-Kahf claimed responsibility for the attack and published a video showing an explosion at a distance. It said it was able to destroy US military equipment and large parts of the crossing.