Iran's Islamic Revolutionary Guard Corps (IRGC) on Wednesday claimed it shot down a U.S. MQ-9 drone and launched a coordinated missile and drone assault on American military installations in Bahrain and Kuwait, as hostilities between Washington and Tehran intensified following fresh U.S. strikes on Iranian targets.The IRGC said the operation targeted key U.S. military facilities, including Bahrain's Fifth Naval District, Bandar Salman and Kuwait's Ali Al Salem Air Base, describing it as retaliation for American military action against Iran.Also read: US resumes strikes on Iran with over 80 targets hit; revokes oil waiver"In an initial response to this aggression, the IRGC Navy and Aerospace Force carried out a joint missile and drone operation, striking 85 key US military facilities" in Bahrain and Kuwait, while also shooting down a U.S. MQ-9 drone, the force said in a statement carried by Iranian state broadcaster IRIB.There was no immediate confirmation from U.S. authorities on Iran's claims regarding the strikes or the reported downing of the drone.Air defences activated in GulfAir raid sirens sounded across Bahrain and Kuwait following the reported attacks. Kuwaiti military officials said the country's air defence systems were responding to what they described as "hostile" missile and drone attacks.The exchange came hours after the United States carried out a fresh wave of military strikes on Iran and revoked a licence that had temporarily allowed Tehran to sell oil on international markets. Washington said the military action was in response to attacks on commercial tankers in the Strait of Hormuz.According to the U.S. Central Command (CENTCOM), more than 60 small boats belonging to the IRGC were among the targets hit, alongside Iranian military infrastructure including air defence systems, coastal surveillance sites, surface-to-air missile batteries, anti-ship cruise missiles and drone launch locations."The unwarranted aggression by Iranian forces is a clear and dangerous violation of the ceasefire and undermines freedom of navigation," CENTCOM said in a statement.Iran's Khatam al-Anbiya Central Headquarters condemned the U.S. strikes as a "blatant act of aggression", warning of a "crushing response" and saying Tehran would not tolerate American interference in the management of the Strait of Hormuz.Also read: Iran vows 'crushing response' after US strikes around Strait of HormuzOil sanctions deepen crisisThe military escalation was accompanied by fresh economic pressure after the U.S. withdrew a key sanctions waiver that had permitted Iran to export crude oil under the interim ceasefire arrangement. The licence, originally due to remain in force until August 21, will now expire early, with Tehran given until July 17 to wind down transactions.Iranian Parliament Speaker Mohammad Baqer Qalibaf accused Washington of violating the ceasefire through military action, renewed sanctions and what he described as interference in the Strait of Hormuz."The era of bullying and extortion is over. We don't fold," Qalibaf wrote in a post on X.Iran's Foreign Ministry condemned the revocation of the oil licence as a breach of the ceasefire framework and said the country would take any measures necessary to protect its national interests and security.Meanwhile, Iranian media reported explosions in Kharg Island, Qeshm Island, Sirik and Bandar Abbas following the U.S. strikes. Iranian state television said several people were injured by shrapnel after an "enemy projectile" struck a commercial pier in Sirik, though no civilian deaths were reported.The latest confrontation has further strained the fragile ceasefire brokered last month to pause the conflict between the United States and Iran. Indirect negotiations in Qatar aimed at reaching a permanent agreement ended last week without a breakthrough, while U.S. President Donald Trump has repeatedly warned that military action could resume unless Tehran agrees to a long-term deal.