Three fires blazed on a Greek-flagged oil tanker in the Red Sea, the United Kingdom Maritime Trade Operations said on Friday, one day after rescuers evacuated its crew in the wake of an assault by Yemeni Houthi militants.

The Iran-aligned Houthis, who control Yemen’s most populous regions, said on Thursday that they had attacked the Sounion oil tanker as part of their 10-month campaign against commercial shipping to support Palestinians in the war between Israel and Hamas in Gaza.

The Houthis first damaged the tanker on Wednesday with repeated attacks that caused a fire and a loss of engine power. A European warship later rescued her crew of 25. The uncrewed vessel was anchored between Yemen and Eritrea, a maritime security source told Reuters on Thursday.

On Friday, UKMTO said in an advisory that it had received reports of three fires on the vessel, which “appears to be drifting.” Later in the day, the Houthis posted a video on social media that purportedly showed them setting the tanker on fire.

The damaged tanker, carrying 150,000 metric tons of crude oil, poses an environmental hazard, the EU’s Red Sea naval mission Aspides said.