Yemen’s Iran-aligned Houthis ​escalated their campaign of strikes against Saudi Arabia on Thursday, trying to shut down the kingdom’s airspace and oil facilities with missile fire that has killed three people this ‌week.

The group said it had struck Riyadh airport, where witnesses saw smoke billowing from a plane, and it warned workers to stay away from energy plants. Saudi officials said debris from an intercepted missile had hit a kindergarten and medical complex.

Read more: Reuters