The U.S. has expressed condolences to the relatives of fishermen who were fired on by a U.S. Navy ship off the coast of the United Arab Emirates on Monday night.

“The Embassy of the United States of America would like to convey its condolences to the families of the crew of a small motor vessel, a press note said, adding that the incident is under investigation.

At least one Indian fisherman was killed and three Indian nationals were seriously injured after USNS Rappahannock, a refueling ship, fired a machine gun on their small vessel, mistaking its intentions as aggressive.

There were a total of six people on the boat, U.S. officials said. According to reports, there were also two Emirati nationals on board. The U.A.E. is home to a large number of low-skilled Indian migrant workers.

India’s Ministry of Foreign Affairs on Tuesday said that Indian officials are in touch with U.S. and U.A.E. authorities to probe the circumstance of the incident. Nancy Powell, the U.S. ambassador to India, earlier Tuesday spoke with top foreign ministry official Ranjan Mathai “to convey her regret for the loss of life, the foreign ministry said in a statement.

While expressing regret about the incident, the U.S. is also defending the response of its navy ship, saying the vessel, which turned out to be a fishing boat, “disregarded non-lethal warnings as it “rapidly approached Rappahannock.

U.S. naval ships are on high alert in the Persian Gulf, which is frequently patrolled by Iranian speedboats. In the past, small boats from the Islamic Republic of Iran’s Revolutionary Guard Corps have threatened Western warships in these waters.

The fatal shootout comes just five months after two Italian naval officers were detained in India after two Indian fishermen were killed in similar circumstances.

The Italian marines, who were on board a commercial ship, fired shots at a small boat off the coast of the state of Kerala after mistaking its crew for pirates.

The incident, which took place in February, caused a diplomatic rift between India and Italy. The two countries have so far failed to reach an agreement on the matter.

While Italy claims the incident happened in international waters, and hence should be investigated in Rome, India insists the matter should stay in its courts.

Monday, the Italian government appealed to India’s Supreme Court to have the criminal charges against the naval officers dropped, challenging an earlier order of the Kerala High Court.

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