Salvage companies ended attempts to tow away an oil tanker in the Red Sea that’s been burning for days following attacks by Yemen’s Houthi militants, the European Union’s naval force in the region said. 

The private salvors have concluded that the “conditions were not met to conduct the towing operation” on the Sounion, EUNAVFOR Aspides said in a post on X. The firms are exploring alternatives, according to the post.  

The failed attempt leaves the Sounion and its 1 million barrels of Iraqi crude cargo anchored in international waters and at risk of an environmental disaster. The ship was hit with missiles on Aug. 21 after rounding the Yemeni coast to enter the Red Sea, and was attacked again on Aug. 23 that caused the fires that are now burning on the vessel. The EU naval force has warned of an ecological crisis due to the large volume of oil on board. 

The EU organization said Monday that there were “no visible signs of an oil spill.”

Yemen’s Houthi rebels have been attacking vessels transiting the southern Red Sea with drones and missiles since late last year in reprisals for Israel’s war against Hamas in Gaza. The attacks have sunk a vessel and killed or injured mariners and forced many shippers to divert traffic to sail around Africa.