An Iranian missile fired during a training exercise in the Gulf of Oman struck a support vessel near its target, killing at least 19, amid heightened tensions between Tehran and the US. The friendly fire incident happened on Sunday near the port of Jask, 790 mile south-east of Tehran, in the Gulf of Oman. Iran’s army said 19 people died and 15 were injured. The missile struck the Konarak, a Hendijan-class support ship, taking part in the exercise. State television described the missile strike as an accident, saying the Konarak had remained too close to the target. The Konarak had been putting targets out in the water for other ships to fire upon, it said. Iranian media said the Konarak had been overhauled in 2018 and was able to launch sea and anti-ship missiles. The Dutch-made, 47-metre (155-foot) vessel was in service since 1988 and had capacity of 40 tons. It usually carries a crew of 20 sailors. Iran regularly holds exercises in the region, which is closed to the strategic Strait of Hormuz, the narrow mouth of the Persian Gulf through which 20% of the worlds oil passes. The US Navy’s 5th Fleet, which monitors the region, did not immediately respond to a request for comment. Iranian media rarely report on mishaps during its exercises, signalling the severity of the incident. It comes amid months of heightened tensions between Iran and the US since President Donald Trump unilaterally withdrew from Tehran’s nuclear deal with world powers in 2018 and imposed crushing sanctions on the country. In January, Iran shot down a Ukrainian passenger plane by mistake shortly after it had taken off from Tehran, killing all 176 people on board.