The U.S. Navy disclosed Tuesday that one of its oil tankers in the Middle East suffered significant damage while at sea, complicating a fraught deterrence mission as hostilities between Israel and Lebanon’s Hezbollah threaten to engulf the region in violence.

The delicate rescue mission aimed to head off a major environmental disaster after the oil tanker was attacked by Houthi rebels off the coast of Yemen last month.

An oil tanker in the Red Sea that was struck by Houthi militants was towed to a safe area after almost four weeks.