Iran summoned a Ukrainian diplomat in Tehran on Sunday to protest an attack on an Iranian commercial vessel in the Caspian Sea, as the war in the Middle East threatened to overlap with the Ukraine conflict.

Iran said the attack left one sailor dead and injured several others. The country's foreign ministry complained to Ukraine's chargé d'affaires in Tehran early on Sunday and "conveyed Iran's strong protest over the 'hostile and criminal act'," Iran's Islamic Republic News Agency reported.