HONG KONG (AP) — A pro-democracy candidate won a Hong Kong weekend by-election while a rival from a radical pro-independence group who's facing riot charges placed a surprising third in a vote seen as a measure of political tension in the Chinese city.

The mainstream Civic Party's Alvin Yeung won the Legislative Council seat with 160,880 votes representing 37 percent of the turnout, edging out pro-Beijing candidate Holden Chow by about 10,000 votes, according to results released early Monday.

But the front-runners were overshadowed by Edward Leung of Hong Kong Indigenous, who garnered 15 percent of about 434,000 votes cast. His group is part of a fledgling movement advocating Hong Kong's independence from China.

The movement has gained support amid growing unease over signs Beijing is tightening its grip on the specially administered Chinese region.

Hong Kong Indigenous is one of a number of groups that sprang up in the wake of pro-democracy street protests in 2014 that ended without a satisfactory resolution as Beijing refused to give any major concessions.

Leung is one of the leaders of Hong Kong Indigenous, which also advocates radical protest methods. He's among dozens of people charged with taking part in a riot following a violent nightlong clash with police at a Lunar New Year holiday street food market earlier this month that was sparked by concerns that the city's local culture is disappearing.

Beijing has condemned groups like Leung's, calling them "radical splitting forces."

Sunday's vote serves as a prelude to citywide elections later this year for the legislature that are expected to be fiercely contested by pro-democracy and pro-Beijing parties.