Iran's Islamic Revolutionary Guard Corps (IRGC) said they launched ballistic missiles from "the depths of the Earth" on Wednesday during the last day of military exercises near sensitive Gulf waters.
It was the latest barrage in a drill that the previous day saw two American bases temporarily go on alert over the launches.
The launches came a day after the Guards struck a mock-up of a U.S. aircraft carrier with volleys of missiles near the Strait of Hormuz, a vital shipping lane for a fifth of world oil output.
State television broadcast aerial footage of the latest daylight exercises in the desert, showing bursts of flames, smoke and then dust before what appeared to be four projectiles climbing into the sky.
The IRGC said in a statement on its Sepahnews website that it was "the first time in the world" that such an exercise had been carried out.
The statement did not elaborate on the claim or provide any of the missiles' specifications.
It hailed "the successful launch of ballistic missiles from the depths of the Earth in a completely camouflaged way" as an "important achievement that could pose serious challenges to enemy intelligence organizations."
The IRGC said they also released bombs from Sukhoi Su-22 fighter-bombers to target predetermined positions on Bani Farur Island in Iran's territorial waters.
"These launches were carried out without the platform and usual equipment," IRGC aerospace chief Brig. Gen. Amirali Hajizadeh said on state television.
"The buried missiles suddenly tear through the ground and hit their targets with precision," he said, adding again that this happened "for the first time in the world."
The maritime maneuvers were staged at a time of heightened tensions between Iran and its decades-old arch-enemy the U.S.
Tensions have escalated between Tehran and Washington since U.S. President Donald Trump unilaterally withdrew in 2018 from a landmark nuclear deal between Iran and world powers.
The sworn enemies have come to the brink of direct confrontation twice since June 2019, when the IRGC shot down a U.S. drone in the Gulf.
Their animosity deepened after Iran's most prominent general, Qasem Soleimani, was killed in a U.S. drone strike near Baghdad airport in January.