CNN was showing video coverage of the event where armed men (festival security? IDF?) were leading festivalgoers away at the start of the Hamas attack. There also appeared to be an armoured vehicle in the background.
I can't find the long form of the video that was shown, but the short form does show a vehicle with the Merkava's characteristic chain and ball design on the turret in the background. It's on CNN's YouTube page and I'll send it to people by request, but it's rather graphic so I'd rather not link it.