By James Pomfret
SHENZHEN, China (Reuters) - Chinese riot police will be deployed for a crunch World Cup soccer 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 spilled over on to the soccer 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 who called for the "beating of Hong Kong dogs" at the Shenzhen game, according to media.
A controversial poster issued by China's National Football Association to promote the qualifier has also raised the heat.
"This team has people with black skin, yellow skin and white skin. For such a diverse team, be on guard!" the poster wrote of the Hong Kong team which has a number of foreign-born players.
Britain handed Hong Kong back to China in 1997 under a promise that core personal and commercial freedoms, backed by a British-style legal system, would be protected for 50 years.
While Hong Kong, soccer minnows ranked just 151 in the world compared to China's 84, are unlikely to cause an upset, some say the political unease could motivate the underdogs.
"We can show them a little bit of our anger, our determination," said Philip Chan, a central midfielder for Hong Kong who took part in the Occupy protests.
"... Even if we lose, we play the game of pride representing seven million people. We're a small city but don't underestimate us."
While most encounters have been peaceful, a 1985 World Cup qualifier in Beijing between the two sides won by Hong Kong sparked riots by rampaging mainland Chinese fans.
This time round, only around 2,200 of the 27,000 tickets were released to Hong Kong fans, who had to register their identity documents ahead of the game.
"The Shenzhen government has prepared well for the match," wrote a mainland Chinese blogger called Dengqiancao. "They have arranged a lot of 'local' fans to support the China team. There's no way for Hong Kong fans to create trouble."
(Additional reporting by Ever Tang; Editing by Nick Macfie)