BAGHDAD (AP) — An unmanned drone dropped explosives on a base belonging to Iran-backed paramilitary forces in northern Iraq early Friday, wounding two people, Iraqi security officials and a military statement said, amid regional tensions between the United States and Iran.

The statement said the drone dropped two grenades half an hour apart on the base in Amirli, in Iraq's northern Salaheddin province. No further details were provided.

There was no immediate claim of responsibility for the attack, which struck shortly after midnight. The Iranian-backed mostly Shiite Muslim militias, in a state...