Houthi rebels attacked a Saudi warship in the Red Sea, killing two sailors and injuring three others, a US official told Fox News.

The warship, Al Madinah, was conducting routine operations on Monday when the attack occurred.

However, it was unknown if the ship was hit by a missile or by suicide attack after being rammed by a small boat, the official said.

The US military was monitoring the situation. The warship was able to continue her transit despite the damage, he added.