Ukraine has targeted ships transporting military cargo in the Caspian Sea, marking a convergence between European and Middle Eastern conflicts as Tehran weighs retaliation.

Iran has vowed retaliation following a strike on an Iranian-flagged cargo ship in the Caspian Sea that killed one sailor and injured three others.

The Middle East conflict has expanded toward the Red Sea and Caspian Sea as Houthi forces strike Saudi oil infrastructure and Ukraine targets an Iranian vessel, while the US pauses direct airstrikes.