A chemical tanker struck Saturday off the coast of India was targeted "by a one-way attack drone fired from Iran," the Pentagon said in a statement.
The attack took place around 10 a.m. local time and caused no casualties aboard the Japanese-owned vessel, it said, adding that a fire was extinguished.
The U.S. military "remains in communication with the vessel as it continues toward a destination in India," it added.
The Pentagon statement said the Chem Pluto ship flew under a Liberian flag and was operated by a Dutch entity.
The drone strike occurred 200 nautical miles off the coast of India, it said, adding that no U.S. Navy vessels were in the vicinity.
There was no immediate claim of responsibility for the strike which came amid a flurry of drone and missile attacks by Yemen's Iran-backed Houthi rebels on a vital shipping lane in the Red Sea. The U.S. on Friday accused Iran of close involvement in those attacks.
The Houthis say they are conducting the attacks in solidarity with Palestinians in the besieged Gaza Strip.
The Indian navy said it had responded to a request for assistance.
An Indian navy official confirmed that an aircraft was sent to assess the safety of a vessel and its crew. The official also mentioned that an Indian navy warship has been dispatched to provide assistance if needed.