In a related development ... security officials of South Korea and Japan say that counter-terrorism, not hooliganism, is their primary concern. Woo Hee-chae is a senior official at South Korea's World Cup Security Control Headquarters. He said the government is taking precautions against all conceivable threats, including nuclear, biological and chemical attacks. He said the government will designate a no-fly zone over World Cup stadia and work out measures against air attacks by terrorists. Meanwhile, an anti-terrorism expert at Japan's National Police Agency, his country has tightened immigration control, visa screening and border control. He said the September eleventh attacks alerted World Cup organizers to new threats and that Asia is now perceived as much more dangerous. The South Korean and Japanese security officials were in Bangkok, Thailand Thursday to brief members of a Southeast Asian regional security forum on their preparations for the World Cup. An Australian security official who attended the meeting said the likelihood of terrorist attacks on the upcoming World Cup is very low.