This is my feeling too. For me, the extract reads like straight history or journalism. One way around this may be to start at '“People’s Militia came into Prague this morning,” says Jarek.'
I think that having told readers in the intro piece that there are three characters, they'll want to get to at least one of the characters quickly. What the characters are thinking and feeling will be the hook, as it were, for this scene.
Regarding the need to give some physical scene setting, I think that paradoxically an excerpt from somewhere during the story needs this more than the opening page of a novel. With an opening, we trust the reader to gradually reveal where we are and what's happening. With an excerpt there's the unsettling feeling of being dropped into the narrative without knowing what has gone before. As a reader I want quick concrete information to let me create an instant picture of the physical setting. You tell us where we are but there are few details to show what it might look like. You don't need many details, but, for instance, are characters being jostled, how far can they see, can they hear the speakers properly.