Liu said Beijing has deployed nearly 110,000 personnel, including policemen, army troops and volunteers, and mobilized the whole society to ensure the security of the Games.

    Beijing’s tight security measures could be easily sensed as the Olympics draws near. From anti-terrorism drills to halt of flights during the opening ceremony, Beijing is taking every possible measure to ward off potential security threat.

    Peripheral fences now encircle all Olympic venues, the Olympic Village and the Olympic headquarters hotels. Monitoring and alarm facilities have been installed with personnel and vehicle security checkpoints set up.

    Armed police with dogs began round-the-clock patrols at the capital’s four railway stations, including the renovated one in a southern district that hasn’t yet opened. Air, rail and long-distance bus facilities are also on heightened alert.

    In the wake of bus explosion cases in southwestern Yunnan province, Beijing security departments have also intensified security checks at bus stations and to public vehicle.

    "Painstaking efforts have been made to strengthen community patrols, crack down on various criminal activities, tighten management of dangerous goods and deploy security personnel in crucial Olympic sites," Liu said. "All in an unprecedented efforts to eliminate potential safety hazards in a timely manner."

    In response to complaints that the security measures are being "excessive" and make the Olympics less joyful, Liu said the measures followed the successful experience of previous host cities.

    "Olympic Games is a large-scale sports event that we’ve never experienced… With huge number of people coming to China, international terrorist forces are seeking chances. Therefore, we have to intensify the security efforts," Liu said.

    "We’ve noticed certain complaints. We’ll pay attention and try our best to make the Games safe and peaceful," he said.

    Asked whether foreign athletes will be allowed to demonstrate their political views through non-violence means at the opening ceremony, Liu said the Olympic Charter has made it clear that "no kind of demonstration of political, religious or racial propagandais permitted in any Olympic sites, venues or areas."

    "People participating the Olympic Games, including athletes and coaches, should observe the regulations of the International Olympic Committee," he said.

    But the official said Beijing did designate several parks for protests.

    "During the Olympics, in order to ensure a smooth traffic, nice environment and good social order, we would like to ask protestors to go to the designated parks," he said, adding it is also a common practice of some countries.

    The official declined to answer how much money Beijing has spent on security, saying that while trying to ensure a safe Olympics, the BOCOG will also spend the money in a thrift way.