Yemen’s Iran-backed Houthi movement claimed on Thursday that it had attacked two Saudi oil tankers in the Red Sea, opening another potential front in the widening conflict between the United States and Iran.

The group said on Telegram that it had carried out a “qualitative military operation” against the Saudi vessels Encelia and Layla, accusing them of violating a maritime blockade imposed on Saudi Arabia earlier this week. The Houthis said the ships were targeted with missiles, although the reported attack on the second vessel has not been independently confirmed.

A British maritime security monitor, the United Kingdom Maritime Trade Operations (UKMTO), reported that a tanker sailing near Saudi Arabia was struck by an unidentified projectile on Wednesday. “The master of a tanker reports being struck by an unknown projectile which has caused a fire onboard that the crew are currently fighting,” UKMTO said. A maritime security source later said the Saudi-flagged tanker Encelia issued a distress call after being hit and catching fire near the Saudi port of Jizan. No casualties have been reported.

The Houthi claims came as the United States carried out its 12th consecutive night of strikes against targets in Iran. US Central Command said American forces hit Iranian military sites, including maritime capabilities, missile and drone storage facilities, coastal surveillance systems and air defense assets.