In this file handout photo made available by the Iranian Army office on Dec 28, 2019, a view of warships during joint Iran-Russia-China naval drills in the Indian Ocean and the Gulf of Oman. An Iranian warship was accidentally hit by a missile during exercises in the Gulf of Oman on May 11, 2020. (IRANIAN ARMY OFFICE / AFP)

DUBAI - One Iranian warship accidentally struck another with a missile during an exercise, killing 19 sailors and wounding 15 others, Iran’s navy said on Monday.

The incident took place at a time of heightened tensions between Iran and the United States since 2018

The incident took place during training in the Gulf of Oman, a sensitive waterway that connects to the Strait of Hormuz through which about a fifth of the world’s oil passes. Iran regularly conducts exercises in the area.

The frigate Jamaran fired at a training target released by a support ship, the Konarak. However, the support ship stayed too close to the target and was hit, state broadcaster IRIB said.

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“The incident took place in the perimeter of Iran’s southern Bandar-e Jask port on the Gulf of Oman during Iranian Navy drills on Sunday afternoon, in which 19 sailors were killed and 15 others were injured,” state TV said, quoting the navy.

Fars news agency quoted an unidentified military official as denying some Iranian media reports that the Konarak had sunk. The navy statement said investigations were undergoing regarding the cause of the incident, student news agency ISNA said.

This AFP graphic shows a map of Iran locating Bandar-e Jask and the Gulf of Oman where an Iranian warship was accidentally 'hit by a missile' during exercises.

IRIB said the Dutch-made Konarak vessel, which was purchased before Iran’s 1979 Islamic revolution, had been overhauled in 2018, and is equipped with four cruise missiles.

The incident took place at a time of heightened tensions between Iran and the United States since 2018, when the United States withdrew from a nuclear deal between major powers and Iran, and Washington re-imposed sanctions on Tehran.

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In this May 11, 2020 photo provided by the Iranian Army, the Konarak support vessel which was struck during a training exercise in the Gulf of Oman, is docked in an unidentified naval base in Iran. (PHOTO / IRANIAN ARMY VIA AP)

Animosity deepened in early January when a US drone strike in Baghdad killed top Iranian military commander Qassem Soleimani. Iran retaliated on Jan 9 by firing missiles at US military bases in Iraq. Later that day, Iran’s armed forces shot down a Ukrainian airliner, killing all 176 people aboard, in what the military later acknowledged was a mistake.