HONG KONG, July 1 (Reuters) - Hong Kong's national security law imposed on the city a year ago guarantees human rights, including freedom of the media and assembly, the city's No. 2 official John Lee said on Thursday.

Lee, acting Chief Executive while leader Carrie Lam is in Beijing, was speaking at a flag-raising ceremony marking the 24th anniversary of the former British colony's return to Chinese rule in 1997, which coincides with the centenary of the Chinese Communist Party. (Reporting by James Pomfret; editing by Anne Marie Roantree and Shri Navaratnam)