Heli-borne snipers, four-layered security cordon around Commonwealth Games venues and exclusive lanes for Games vehicles are among the components of a mammoth security plan unveiled by the government for the mega sporting event. Unveiling the plan, Delhi Police Commissioner Y S Dadwal told reporters that it also envisages snipers on rooftops, commando hit teams and expert groups to tackle any chemical, biological, or nuclear attacks. According to the plan, the Games venues, Games Village, practice areas and parking lots as also the Indira Gandhi International Airport where athletes will arrive will have a four-layered security cordon. The security plan prepared for the event will see participation from around 8,500 athletes from 71 countries competing in 17 events.<br/><br/>