@Rada74 They've broken the house rule you clearly defined and ask them to agree to before booking. Send them a message on the platform and paste in the relevant rule as reminder. It's up to you what you do after that. This is grounds for immediate cancellation of the remainder of their stay. You can call Airbnb after sending them the message. Advise of the broken house rule and that you don't feel safe. You should, regardless, direct them to immediately have these unregistered guests leave, and if they don't respond, you may have to knock on doors and roust them yourself.