Iran warned on Thursday that the shaky ceasefire in the three-month war was now "practically meaningless" following fresh strikes by the US that saw Tehran respond with attacks around the region.

The war, which began on 28 February with an opening salvo of US-Israeli strikes on Iran, was paused by the April truce, but efforts to hammer out a permanent end to the fighting have stalled, and sporadic exchanges of fire have put the ceasefire under repeated strain.

In their second straight day of tit-for-tat attacks, Washington hit surveillance, communications and air defence facilities, US Central Command (CENTCOM) said, while the IRGC announced a "punitive operation" targeting a US base in Jordan and Gulf states reported incoming fire.

Iranian state-run media reported explosions near the Strait of Hormuz, with explosions heard in Bandar Abbas, Qeshm and Minab, and "enemy projectile" strikes in Kargan and Sirik.

CENTCOM said later that it had "completed" its strikes on "Iranian military surveillance capabilities, communication systems, and air defence sites".