The next teaching day, just say something to them like: Last class was rough. I needed feedback from you guys and not getting any threw me off, which just made everything awkward. So, I'm sorry for a bad lecture day. We all have off days, so I'm going to assume you had one too. In the future, I expect you to be prepared to answer questions and if nobody answers I'm going to call on you directly. Something like that. That's what I would do.
I always own up to my mistake/issue because that lets them know I am human and that I care which makes me holding them accountable more palatable.