Hong Kong and China fans will be kept completely separate at their crunch World Cup qualifier Tuesday, using different entrances and even different toilets as organisers try to head off tensions following last year's pro-democracy rallies.
Around 1,200 police officers will be on standby for the match, according to local media reports, or about one for every five fans at Hong Kong's 6,000-seat Mong Kok Stadium.
Officials have also warned fans to behave themselves after booing of Hong Kong's "March of the Volunteers" anthem -- which the territory shares with China -- prompted FIFA to fine the Hong Kong Football Association more than $5,000.
"We are separating the audience from mainland China and Hong Kong, even for the toilets," HKFA chairman Brian Leung said Sunday.
"I think the chances of them meeting each other is very, very little," he added. "I urge fans to stay calm... show your sporting spirit."
Football fans jeering the anthem in semi-autonomous Hong Kong, ruled under Deng Xiaoping's "one country, two systems" principle, follows a souring of sentiment towards Beijing.
The densely packed Mong Kok commercial district was also the scene of the most violent clashes between police and protesters during last year's "Umbrella movement" pro-democracy rallies.