The attack came amid a flurry of drone and missile strikes by Yemen's Iran-backed Huthi rebels on a vital Red Sea shipping lane since the start of the Israel-Hamas war on October 7, with the group claiming to act in solidarity with Gaza.

Saturday's attack took place around 10 am local time (0600 GMT) and caused no casualties aboard the vessel, it said, adding that a fire was extinguished.

The US military "remains in communication with the vessel as it continues toward a destination in India," it added.

The drone strike occurred 200 nautical miles (370 kilometers) off the coast of India, it said, adding that no US Navy vessels were in the vicinity.

It was the first time the Pentagon has openly accused Iran of directly targeting ships since the start of Israel's war on the militant group Hamas, which is backed by Iran.

The Pentagon statement said the MV Chem Pluto ship flew under a Liberian flag and was operated by a Dutch entity, although the ship is owned by a Japanese company.

Ambrey, a maritime security firm, said the "chemical/products tanker... was Israel-affiliated" and had been on its way from Saudi Arabia to India.

The Wall Street Journal reported that the Dutch company operating the MV Chem Pluto "is connected to Israeli shipping tycoon Idan Ofer."

The Indian navy said it had responded to a request for assistance.

"An aircraft was dispatched and it reached overhead the vessel and established safety of the involved ship and its crew," a navy official told AFP.

"An Indian navy warship has also been dispatched so as to provide assistance as required."

There was no immediate claim of responsibility for the strike.

Last month, an Israeli-owned cargo ship was hit in a suspected drone attack by Iran's Islamic Revolutionary Guard Corps in the Indian Ocean, according to a US official.

The Malta-flagged vessel managed by an Israeli-affiliated company was reportedly damaged when the unmanned aerial vehicle exploded close to it, according to Ambrey.

The Red Sea attacks on shipping since the start of the Israel-Hamas war have prompted major firms to reroute their cargo vessels around the southern tip of Africa, despite the higher fuel costs of much longer voyages.

The Huthi rebels have launched more than 100 drone and missile attacks, targeting 10 merchant vessels involving more than 35 different countries, according to the Pentagon.

On Saturday, an official in Iran's Revolutionary Guard warned of the forced closure of other waterways unless Israel halted its war with Hamas.

"With the continuation of these crimes, America and its allies should expect the emergence of new resistance forces and the closure of other waterways," Mohammad Reza Naqdi said, quoted by Iran's Tasnim news agency.

Among the waterways he mentioned was the Mediterranean Sea. He did not elaborate.