A major oil spill from a suezmax tanker attacked by Yemen’s Houthi militia could leave insurers facing payouts of more than $600m even with the Greek shipowner limiting its liabilities with affected coastal states.

The 163,759-dwt Sounion (built 2006) continues to burn following a wave of attacks over three days last week, and the US military said late on Tuesday that it appears to be leaking oil.