Yemen’s Houthi group on Tuesday threatened to attack royal palaces in Saudi Arabia.

Speaking at a press conference in Sanaa, Houthi spokesman Yahya Saree called on Saudi civilians and residents to stay away from palaces of Saudi officials.

“These palaces have become on the list of military targets by our forces,” he said in statements cited by the Houthi-run Al-Masirah TV.

The spokesman said his group has targeted “sensitive” sites in Saudi Arabia, but without giving further details.

There was no comment from Saudi authorities on the Houthi threat.

On Friday, Houthis claimed drone attacks on an airport and airbase in western Saudi Arabia.

Yemen has been beset by violence and chaos since 2014, when Houthis overran much of the country, including Sanaa. The crisis escalated in 2015 when a Saudi-led military coalition launched a devastating air campaign aimed at rolling back Houthi territorial gains.

Tens of thousands of Yemenis, including civilians, are believed to have been killed in the conflict, which has led to the world’s worst humanitarian crisis as millions remain at risk of starvation.

-Agencies