BAGHDAD (AP) — Iraqi security officials say an unmanned drone has dropped explosives on a base belonging to Iran-backed paramilitary forces in northern Iraq, wounding two people.

Two officials said the incident occurred overnight on the base in Amerli, in Iraq's northern Salaheddin province. Speaking on condition of anonymity in line with regulations, they said the drone dropped a grenade on the base. No further details were provided.

There was no immediate claim of responsibility for the attack, which comes amid regional tensions between the United States and Iran. The tensions have left Iraq's government, which is allied with both sides, in a delicate position.

Iraq is home to U.S. bases and troops as well as dozens of Iran-backed militias.