I've actually seen this happen in all the tiers at one time or another. Seems to be a spawn point nearby. We cleared the area out of klingons and went on our merry way. I few battles later I went boom and when I respawned there were 3 birds of prey and 2 warships sitting there. The first time I went boom, the second time I tried to lead them away before going boom. The third time I went boom a whole bunch of colorful metaphors could be heard wafting through my house. The 4th time I wanted to find a dev and shove my keyboard somewhere uncomfortable. I couldn't even warp out. Luckily the servers went down shortly thereafter.