I was in the Army (Australia), and on New Years Eve 1993 I was at an NYE party in Darwin. It was very humid, so humid that a thick fog had settled some ten or so metres above the ground. and the clouds above were very low. The street lights at the time were the orange ones, and when they were on inside a blanket of fog, they made the fog also orange and difficult to see though (looking upwards past to the clouds) That night I as not drinking as I was the driver for my wife and kids.
Around 2300Hrs we noticed three bright slow moving lights, in a line through the fog and clouds. The last light would fly "over" the other two and go to the front, then the now last light would do the same but "under" the other two, and this leap-frogging continued from one side of the sky to the other. Being Darwin in the 90's a lot of people still owned guns, so my mate, the host went and grabbed his .308 with a decent scope and we tried looking through the scope to see what was going on. Every time we got a break in the fog and clouds the lights seen, still appeared blurred, also to note the three lights were the same colour as the local orange street lights.
We decided to call the duty room at Larrakeyah barracks, as we knew the Duty Officer, and the Corporal that was on that night (Everyone had a roster, for their turn in the barrel). After getting through to the Corporal we knew, we asked if anyone had called about weird shit. Given that we were in a large patch of military housing, every man and his cat had been calling them. He told us Darwin Airport had picked up radar signatures, as did RAAF Darwin, but not RAAF Tindal (some 320km South-ish) suggesting they were low flying. He then said RAAF Tindal had been called and they were in the process of scrambling two F/A-18's from No.75 Sqn (Fighters), and that also he did not talk to us, nor did they call the RAAF, nor did they scramble two fighters. (It sounded like there was at least another three people with them in the duty room, when it's usually two people, and we could hear people on radios and phones in the background).
Within a few minutes the lights and made it to the horizon that we could see from the roof of the house and a short time later we could hear two fighters. (Flight time from RAAF Tindal is about 12 minutes to move 320-ish km's using afterburners) and that was the last we saw or heard of anything.