Buddhists are no exception. Sad as it may be, such atrocities are not unprecedented and have accompanied Buddhism throughout its history; just as they have accompanied any other faith.
If you are interested, the book "Buddhist Warfare" collects a few interesting essays on the topic: https://www.amazon.com/dp/0195394844
Buddhism, from it's source, is different in that its first espouser categorically denounced violence against all living things, which makes any Buddhist warfare a shocking example of human ills. The Buddha even goes as far as to denounce just retribution.