DOHA (Reuters) - Unknown assailants attacked an oil tanker on Wednesday in a strategic Red Sea waterway near Yemen in the latest flare-up in an area through which much of the world’s oil passes.

The EU Naval Force said in a statement that the attackers fired rocket-propelled grenades before breaking off their assault on the Marshall Islands-flagged tanker MT MUSKIE in the southern Bab al-Mandab Strait. The tanker is 70,362 tons deadweight.

A spokesman for the EU force said the attack did not appear to have been launched by pirates and was likely related to “continuing instability at sea off the coast of Yemen.”

Vessels near Yemen’s southern coast have been attacked in recent months by Houthi militants who are fighting against Yemen’s Saudi-backed government in a civil war that has left millions of people starving.

Nearly four million barrels of oil are shipped daily to Europe, the United States and Asia via the Bab al-Mandab, as well as other commercial goods.