Iran on Monday released pictures showing two gaping holes in the hull of an oil tanker it alleges was attacked off Saudi Arabia last week.  

Tehran says the Iranian-flagged Sabiti tanker was hit by two separate explosions off the Red Sea port of Jeddah on Friday. It is the first Iranian ship to have been targeted since a spate of attacks on vessels in the Gulf that Washington blamed on Tehran.  

The images released by the tanker's owner, the National Iranian Tanker Company, are dated Sunday and show two holes above the waterline on the ship's starboard side.

The attack caused oil to spill from the tanker into the Red Sea, the NITC said, before it was eventually controlled and the vessel began slowly moving back towards Gulf waters.  

The incident follows a series of unexplained attacks in May and June on shipping in and around the Gulf, a vital waterway linking oil-producing countries to world markets, as well as drone attacks on Saudi oil installations.  

Washington accused Tehran of attacking the vessels with mines and to be behind the drone assault, something it strongly denied.  

Iran said that the "cowardly" attack on its own tanker was caused by a missile strike and vowed not to let it go unanswered. But the state-owned NITC denied reports the attack had originated from Saudi soil.