A rebel group called the Houthis is attacking Saudi Arabia's oil sites. The Houthis are based in Yemen and backed by Iran.

They are also blocking ships in the Red Sea. Yemen says it is ready for more Houthi attacks.

This follows Houthi strikes on Saudi Arabia. The conflict could grow into a bigger regional fight.

It also threatens ships passing through the Red Sea. From July 22 to 23 the Houthis claimed missile and drone strikes on two Saudi oil tankers.

Saudi Arabia confirmed one tanker was hit. The ship was called the Encelia.

The European Union and a US-led safety group called JMIC warned ships to avoid the area. They told ships linked to Israel, the United States or Saudi Arabia to stay away.

Saudi Arabia has been sending oil through a different port to avoid danger. That port is called Yanbu and sits on the Red Sea.

Oil shipped through Yanbu jumped to 3.5 million barrels a day in June. The Houthis are using Saudi Arabia's weak moment to gain power. They hope to force political changes in Yemen through these attacks.