An Iranian Revolutionary Guards commander said the Mediterranean Sea could be closed if the United States and its allies continued to commit "crimes" in Gaza, Iranian media reported on Saturday, without explaining how that would happen.

Hamas is against Israel and it accuses the United States of backing what it calls Israeli crimes in Gaza, where weeks of bombardment have killed thousands of people and driven most of the population from their homes.

"They shall soon await the closure of the Mediterranean Sea, (the Strait of) Gibraltar and other waterways," Tasnim quoted Brigadier General Mohammad Reza Naqdi, coordinating commander of the Guards, as saying.

Houthi group has over the past month attacked merchant vessels sailing through the Red Sea in retaliation for Israel's assault on Gaza, leading some shipping companies to switch routes.

The White House on Friday said Iran was "deeply involved" in planning operations against commercial vessels in the Red Sea.

White House says it’s monitoring Red Sea attacks; not seeing big impact on holiday products

Iran has no direct access to the Mediterranean itself and it was not clear how the Guards could attempt to close it off, although Naqdi talked of "the birth of new powers of resistance and the closure of other waterways".

"Yesterday, the Persian Gulf and the Strait of Hormuz became a nightmare for them, and today they are trapped ... in the Red Sea," Naqdi was quoted as saying.

The only groups backed by Iran on the Mediterranean are Lebanon's Hezbollah and allied militia in Syria, at the far end of the sea from Gibraltar.