People from the other universe.
They are certainly not attempting to be subtle or inconspicuous. Even before the fight broke out, the female of mixed species was dressed in such a … "fashion", for lack of a better word … as to make almost every sentient in the sector sit up and take notice. Of course, now that they have already been found by Mister Travis and seen by everyone else, contacting them clandestinely will be difficult. I may even be required to mount a rescue operation of sorts.
Or...
There has to be a logical reason for behaviour which appears, on the surface, to make no logical sense whatsoever. Clearly, these are trained personnel from the other universe's military service; why would they come aboard Terok Nor so openly, and immediately allow themselves to be identified?
Perhaps, this is merely a feint. They may be more of them, operating in secret, while this group operates purely as a distaction. I shall have to maintain observation from a distance, and not get directly involved yet.
It has been years since we have been able to contact the other universe through transporter technology, or since anyone from that universe arrived here by such means. Perhaps that method no longer functions due to a change in conditions between our two universes - I have heard theoreticians suspect as much, without being able to find any means of testing their hypothesis. Either the theories are wrong, or something else has changed, or…
Or… they got here through different means. Perhaps … a ship?