A chemical tanker was hit by a drone launched from Iran in the Indian Ocean on Saturday, the US military announced.
The Pentagon said the Chem Pluto vessel was struck "200 nautical miles (370km) from the coast of India" at 10:00 local time (06:00 GMT).
A fire on board the ship was extinguished. There were no casualties.
Iran has not commented. There has recently been a series of drone and rocket attacks on ships in the Red Sea by Iran-backed Houthi rebels in Yemen.
In a separate development, the US Central Command (CENTCOM) said that on Saturday "two Houthi anti-ship ballistic missiles were fired into international shipping lanes in the Southern Red Sea from Houthi-controlled areas of Yemen. No ships reported being impacted by the ballistic missiles".
It also said the USS Laboon warship patrolling the area "shot down four unmanned aerial drones originating from Houthi-controlled areas in Yemen that were inbound" to the American vessel.
Later that day, a crude oil tanker reported being hit by a Houthi drone in the southern Red Sea, while another tanker saw a near miss.
Many large global shipping groups have suspended operations in the Red Sea due to the increased risk of attacks.
In a statement, the Pentagon said that Chem Pluto was hit by "a one-way attack drone fired from Iran".
It said it was "a Liberia-flagged, Japanese-owned, and Netherlands-operated chemical tanker".