... in Israel when the "authorities" (or settlers) show up, that's when it gets ugly. I was in dozens of demonstrations between 2000 and 2005, and this was usually the case -- although not always. As for the numbers, I suspect the group was much bigger than 5000 -- also in my experience the media grossly underreports the numbers at demonstrations.
Clashes between IDF and protesters in Bethlehem and East Jerusalem (Reuters)
from the article: Thousands of protesters rally against Jewish presence in East Jerusalem