Here is the problem, I am only syncing Users from a DomainA. Due to acquisition I now see bunch of users from DomainB in the user profile thus they are showing up in the people search with just their id. For example, DomainB\userID1. I verified in the "Configure Sync Connections" and made sure no other domains are being synced.
How do I remove these unwanted people from user profile db? After this crawl should automatically remove them.