Greece has advised commercial vessels sailing in the Red Sea and the Gulf of Aden to avoid Yemeni waters, keep only the necessary crew on the bridge and follow alerts issued by maritime authorities to avoid attacks in the area.

Greek ship-owners control about 20 per cent of the world’s commercial vessels in terms of carrying capacity.

A shipping ministry advisory was issued as recent attacks by the Iran-aligned Houthi militant group on vessels have forced leading shipping companies to reroute via the Cape of Good Hope to avoid the Suez Canal, the shortest shipping route between Europe and Asia.

According to a document seen by Reuters, vessels should also conduct fire drills for regular checks of their safety equipment before they reach Yemeni shores, and are advised to sail through the southern Red Sea and the Bab-el-Mandeb Strait at night.

The Houthis, who control much of Yemen, say the shipping attacks are a response to Israel’s military campaign in the Gaza Strip and have said they will continue until Israel stops the offensive.