SHENZHEN (REUTERS) - Chinese riot police will be deployed for a crunch World Cup football qualifying match on Thursday between China and Hong Kong that could reignite tensions that have lingered under the surface since Hong Kong's massive anti-China protests last year.

Chinese police have conducted days of anti-riot drills outside a 40,000-seat stadium in the southern city of Shenzhen, bordering the Chinese "special administrative zone" of Hong Kong.

Media said more than 1,000 police would be deployed with the Shenzhen Public Security Bureau warning unruly fans could be fined or detained.

Protesters blocked key Hong Kong streets for months in last year's "Occupy Central" protests, calling for real democracy for the former British colony in the vote for its next leader in 2017.

Beijing has allowed a direct vote, but only from among pre-screened, pro-Beijing candidates. Passions spilt over on to the football field this year when Hong Kong fans jeered at two qualifiers when China's national anthem was played, drawing the ire of some mainland bloggers.