normally organized plan -- a fairly large explosion there, a stun grenade -- and it encourages peaceful protesters to go home. i've been watching 15 hours more or less of standoff, and a massive volley of tear gas about three hours ago. you have to ask yourself how does this end, what is the administration's end to calm istanbul and do they want pictures like this playing out for another 15 hours? >> if you're just tuning in, you're watching live pictures from taksim square in downtown istanbul where protesters and police have been clashing for hours. our own nick paton walsh is in taksim park, as well as arwa damon.