An Indian mariner who was on board a Marshall Islands-flagged oil tanker in the Gulf of Oman was killed on Monday after a bomb-carrying drone boat struck the vessel, AP reported.

The Indian citizen was on board the MKD Vyom, which was attacked off the coast of Muscat. This was the first Indian casualty in the ongoing conflict in West Asia.

The Indian Embassy in Oman said it is in close coordination with local authorities “to facilitate the safe and early repatriation of our nationals on board the vessel”.

It was not immediately clear who launched the attack. However, Iran is believed to have launched have several attacks on vessels approaching the Strait of Hormuz, a narrow channel that connects the Persian Gulf with the Gulf of Oman and Arabian Sea.

Iran shares control of the strait with the Musandam Peninsula of Oman.

West Asia has been mired in conflict since February 28, when Israel and the United States launched an operation targeting the Iranian regime, claiming that it was necessary “to remove existential threats to Israel”.

Israel has been claiming that Iran is “closer than ever” to obtaining a nuclear weapon, which could alter the regional security balance.

On Sunday, Iranian Supreme Leader Ayatollah Ali Khamenei was killed in the US-Israeli military operation. His killing further escalated an already volatile situation in the region.

Iran retaliated to the attacks and said that the US-Israeli operation had begun while negotiations about its nuclear programme were on.

The Iranian Red Crescent said on Monday that 555 people have been killed over two days across the country since the United States and Israel began their operation.