Reports suggest that a number of journalists were banned from covering the handover celebration events after a security background check.
Journalists banned are from outlets such as HK01, SCMP, Now TV, Ming Pao, AFP.
EDIT: Journalists who did not pass the background check include those from the HK Govt's own news bureau, and also the Liaison Office controlled Ta Kung Pao.
https://twitter.com/krislc/status/1541786471019028482