New york: Iran's permanent mission to the UN has denounced the US for 'piracy' after US military forces attacked an Iranian commercial vessel in the Sea of Oman. In a letter addressed to UN Secretary-General Antonio Guterres and the presidency of the UN Security Council, Iran described the incident as a hostile and unlawful attack.According to Islamic Republic News Agency, the letter was written by Iranian Ambassador and Permanent Representative to the United Nations Amir Saeid Iravani. It condemned the US military's actions on April 19, 2026, against the Iranian commercial vessel 'Toska', citing acts of coercion and intimidation that endangered the vessel's crew and their families. The letter appealed to the UN to address what Iran perceives as an act of piracy and a violation of international law.The letter emphasized that this attack on a civilian vessel violated fundamental principles of international law, including the prohibition against aggression. Iran argued that the intimidation and psychologica l impact on the crew and their families exacerbated the severity of the incident, which posed a threat to vital shipping lanes and regional security.Moreover, the letter claimed that the US action breached the ceasefire of April 8, 2026, and constituted an act of aggression as defined by international resolutions. Iran called on the United Nations, particularly the Security Council and the Secretary-General, to condemn the attack and demand accountability from the US, including the immediate release of the vessel and its crew.Iran's mission requested that the letter be circulated as an official document of the Security Council, underscoring the urgency and gravity of the situation.