Yes, use a section break. This is a change in PoV. One recommendation, though. Assuming that the other sections have been in a close third person or a first person PoV, I would use an objective omniscient, i.e., do not dip into any character's thoughts or feelings. If there is a need to show thoughts and feelings, then I would go with a new PoV from a character perspective.What would be the best approach to introduce this omniscient narrator with no (apparent) POV? For instance, in other threads some use graphical elements to mark a change in POV (I've picked ###), but this situation is different; The POV is now omniscient.
It is often useful to build tension by giving the reader some information that is not known by the main characters. Switching to a different PoV, even for only a short section, is not unusual and should not be jarring to readers. The section break is a clear identifier, but it also should be apparent early in the section, perhaps even in the first sentence, that the PoV has changed.