it was captured on videos that mainly homeless hobos youths and children were pushed and responsible of making this mess under the cover of the real protesters who took the beating instead of them. the situation now is that Islamists are focusing on elections while young youth parties are pushing for protests just for the sake of it. your statement about ultra-fundamentalists is true to some extent yet its very unlikely that they are responsible for this.
U.S. warns governments, bankers Iran sanctions still in place (Reuters)
from the article: Egypt riots threaten cultural sites as Cairo library goes up in flame