4 Extremely Bright Stationary Flashes

At approximately 0110 in the morning, Tuesday, 5 June, 2018, I had to let the dog out to do his business.  Weather was clear, very slight high haze and a couple of random puffy clouds.
While waiting for the dog to finish, I observed several passenger aircraft cross the sky from west to east, very normal.
I then looked to the south/southwest, approximately 65 degrees above the horizon.  Four extremely bright, almost dazzling, pinpoint-like flashes occurred in quick succession.  The first 3 flashes were timed about 1 second apart with the last flash happening about 3 seconds after the third.  The flashes did not move relative to each other, and were in the exact same location for each flash.  I was very taken aback by how bright the flashes were.
As there was zero motion between flashes, it could not have been an aircraft, satellite or meteor, and the flashes were located much too high to be a drone or other hobbyist device. I did not observe any smoke or other pyrotechnic residue, not that I would expect any this late at night.
I continued to intently observe this particular portion of sky for another 5 minutes, but I did not observe any further activity.