S.T.A.L.K.E.R. Shadow of Chernobyl

I once stumbled upon them while heading to the initial outpost in the late game. A group of seven was there, and I, along with three other stalkers who were camping under the bridge, got caught in a firefight. I was the only one who survived. That's it.

Added after 9 hours and 51 minutes
Another bug! The quest to protect the initial stalker outpost doesn't work properly when some "givi" claim it. Specifically, not all stalkers take cover, resulting in the "givi" shooting everyone right at the beginning of the village and killing many bots. IMO, it's better to go out and take them all down yourself.