Seems strange for Buddhists.
Myanmar borders Bangladesh. There appears to be a lot of illegal immigration into Muslim areas of Myanmar from there. The Buddhists are afraid of getting overrun.
Not strange at all. Buddhists are human, after all. One of the most vicious historical episodes involving Buddhists occurred in Japan in the late 16th century, when Buddhist monks devised and implemented ways to torture Christians (in addition to crucifying them by the score).