From the article, it looks like people protesting a govt decision, nothing like Libya or Egypt protesting their form of govt.
Most of Croatia was never under Muslim rule, and the small part that was, was reconquered from the Turks more than 300 years ago. The country is predominantly Catholic. There are a few Muslims (Albanians or Bosnians) but they can't be more than 3% of the population (judging from the
World Almanac data which gives percentages of Catholics, Orthodox, and "none").
From what I've read, the government has been pushing the idea of joining the EU but the population is very divided on whether it's a good idea--perhaps less than 50% are in favor.