Archaeologists working at Chichen-Itza have uncovered the bones of six human beings in a sink hole. The humans were ritually sacrificed some time between 850-1250 AD. To read more about the find and see some amazing pictures, check out this National Geographic Article.
Interesting but not surprising. Variation in human cultures seems almost limitless, but they all seem to me to have two things in common, religion and aggressive behavior. Although not proven that I know of, it seems strongly circumstantial that Homo Sapiens is responsible for the extinctions of numerous species, including the mammoths, the saber-toothed tigers, horses in the new world, and the Neanderthals. We are dangerous.
Yes, and the Maya are known for practicing human sacrifice. This is just one of the few examples (and I believe the only one at Chichen-Itza) uncovered that definitively demonstrate the action under the Classical Maya.