UFO Sighting in Wilkes-Barre, Pennsylvania on July 4th 2015 – Multiple orb-like objects sighted, which at times trailed flames or sparks

I went outside with our 2 dogs so they could perform their nightly "duties". I usually take my phone with me in case they decide to dawdle, but since fireworks were going off I didn't anticipate either of them being out very long, so I unfortunately did not have it with me. Less than a minute after I went out, I observed the first of the objects moving slowly from roughly NE to a southerly direction while looking up for fireworks. It was not traveling in a straight line, but rather a somewhat meandering path. The object did seem to favor turning toward its left (my right) more than any other direction. On 2 occasions during my first sighting, it appeared to emit either flames or sparks from what I can only assume would be the rear of it (It could have been the bottom, as none of the objects ever got close enough to view any type of definite shape). The emissions only lasted for at most 3 seconds, and they reminded me very much of the "trails" left behind while someone is welding, with pieces of glowing metal staying lit slightly longer than the sparks from the weld itself. When I first sighted it, I assumed it was nothing more than a roman candle or some such type of firework, but I immediately discounted that when the light neither faded nor moved toward the ground in a downward arc. My next thought was a helicopter, but I've heard them fly overhead many times before and even with all the noise from the fireworks around me, I could not discern any sound from the object. By this time, the object seemed to speed up a bit while moving over the roof of our home, so I immediately took the dogs in and called for my fiancee. She arrived a few seconds later, and when I went into the backyard in an attempt to reacquire sight of the object, I was unable to see it. I started around the side of the house for a better view of the southern sky when she called to me from the back porch. She had sighted not only 1 but 3 identical objects - one at a heading (that I confirmed after the sighting was over via my phone's compass) of roughly 290 degress magnetic, while the other 2 seemed to be much closer to each other at approximately 310 degrees magnetic. One of those objects seemed to be slightly lower an to my right of it's mate, but since they were apparently very far away I was unable to determine if that was actually the case or if one of them was simply lower to the horizon than the other. It may have been possible that these were 3 additional objects from my original sighting as I have no way of knowing if my initial object circled around to join the "group". I immediately ran inside to grab my phone, but by the time I got back outside 2 of those 3 objects had vanished. My fiancee verified the flames/sparks that I observed - they came out of each of these new objects, but not in unison. I originally got some still shots using my "perfectly clear" app on my phone, but then realized that app does not shoot video, so I had to switch over to the stock Android camera app for that. I was not sure if the videos were actually being shot, so that is why I have multiple videos before the final one. Just as with the other 2 objects she observed, the final one either ascended into the sky until it was no longer visible or the light slowly faded on it. A few final observations: While taking the stills and videos I thought they might be drones of some sort (I own one myself), however I have yet to see one that's capable of carrying a payload that would emit the flames/sparks...I assume that would be far too heavy for a civilian drone to carry. Also, I would like to state that my fiancee is a management official at a local health care facility, and she is FAR more skeptical about anything out of the ordinary than I am, and even she has no explanation for what they were, and was slightly shaken afterward. PS: I have more photos and a couple very short videos that I am unable to attach, but none of them show any more detail than the ones I have attached below. Thank you so much for your time.