The Hong Kong government says it has barred a young pro-democracy activist from an upcoming election because her party's political platform violates electoral laws, in the latest move by the semiautonomous Chinese city to squelch dissent.

An official statement Saturday says a female candidate's nomination was ruled invalid.

She was not identified but 21-year-old Agnes Chow, a member of democracy activist Joshua Wong's Demosisto party, confirmed it was her.

Chow is the latest to fall victim to the Beijing-backed government's tightening restrictions on opposition candidates.

She was planning to stand in a March by-election but the government said the returning officer decided she couldn't be a candidate because of Demosisto's platform, which advocates "self-determination" or independence for Hong Kong.

Chow told reporters the disqualification was "political screening."