The spokesman for the Saudi led coalition’s Joint Forces Command says it will issue a warning for civilians near a site in Sanaa, Yemen, to evacuate ahead of an upcoming “qualitative operation.” The site and the nature of the operation have not been announced.

The warning follows a week of escalation. The coalition launched operation “Dawn of Yemen” on October 4 in support of Yemeni government forces, claiming 324 high value targets destroyed on the first day. After a series of Houthi attacks on Saudi airports, including a Saturday missile strike on Riyadh’s King Khalid International Airport that killed at least 12 people including one American, Saudi Arabia vowed to retaliate firmly. The coalition said last week it destroyed 82 Houthi targets in response to attacks on civilian infrastructure.