Bulgarian media offer have different opinions about the number of participants.
Darik.bg still claims 400 protesters (last edit 17:19)
News.bg claims 1 200 protesters (last edit 17:52)
Bulgaria e nasha already posted a summary of the protest. The blog is in Bulgarian, but contain fresh pictures
They say that less people attended than one week ago, and the most heard demand was the resignation of Minister of interior affairs Michail Marinov. The protestors sees him as responsible for the violence 14th of january, and for the deah of Metodi Marinov in custody 15th of January. this scandal is as far as I understand not connected directly to the protests the same 24 hours.
As last week music was played an important part of the protest, with Scorpion's Wind of Change as alead melody.