Yemen’s Iran-aligned Houthis said on Monday that they had targeted a Saudi military vessel and four escort ships in the Red Sea with missiles.

Houthi military spokesperson Yahya Saree announced the attack on Telegram. There was no immediate confirmation from Saudi authorities.

The reported attack comes days after the Houthis targeted a vessel near the Bab el-Mandeb Strait, at the southern entrance to the Red Sea. Yemen’s transport ministry said four crew members were killed in that attack.

The Bab el-Mandeb is a strategic maritime chokepoint linking the Red Sea to the Gulf of Aden and is a major route for international shipping.

In July, the Houthis announced a naval blockade against Saudi Arabia in the Red Sea, accusing Riyadh of imposing a siege on Yemen. Saudi Arabia has denied the allegation.