Somewhere between 50,000 to 250,000, marched, in what appears to be positions on the 'extradition to mainland China' issue.
In some ways, this article follows up on the previous posting here in Protest Tracker, whereat there were some assumptions that certain events were bound to materialize which may not have been spoken directly.
Primary of these, are that an atmosphere of protesting has started to incubate, the extradition issue perhaps one of the major sparks. The march that you see here, given it may have unique and peaceful dimensions, still is the entity that fills the expected to be filled lacuna, -or blank, or void, are other word choices.
AP story of event here:
https://www.apnews.com/4dc00ce27b3b467f97c9e4d47d1e2042