Osaka police held a drill Friday to prepare for possible nuclear, biological and chemical attacks on Kansai International Airport.
The measures were part of moves to tighten security against terrorism. Law-enforcement authorities have been on high alert since Japan began dispatching members of the Self-Defense Forces to Iraq and nearby countries in recent weeks.
The al-Qaeda international terrorist network reportedly warned late last year that it would attack Tokyo as soon as SDF members set foot in Iraq.
In the drill, police simulated an attack in which bags containing an unknown chemical explode in several locations at the airport, causing airline crews and passengers to collapse with breathing difficulties and eye irritations.