There a lot of Muslims in Southern Thailand. They are causing trouble there. I don't know the reason for this coup.
Thailand is 95% Buddhist.
It's been a few years, but Thailand used to have so many coups that it became almost like a joke, with various generals overthrowing each other on regular intervals and the rest of the country just carry on as normal.
In this case the current PM has been extremely unpopular, even though he is scheduled to step down in the Nov election, guess some of the previously sacked militaty factions just couldn't wait ...