Police repeatedly scuffled with protesters as Olympians and dignitaries carried the Olympic torch through snowy London during a chaotic relay Sunday. Demonstrators tried to board a relay bus after five-time Olympic gold medalist rower Steve Redgrave launched procession at Wembley Stadium - presaging a number of clashes with police along the torch's 31-mile (50-kilometer) journey. In west London, a protester tried to grab the torch out of the hands of a TV presenter, forcing police to briefly stop the procession as officers detained the man. Another demonstrator tried to snuff out the flame with what appeared to be a fire extinguisher. Others in the crowd threw themselves at torchbearers running past in official Beijing 2008 Olympics tracksuits. The protests have forced officials to make unscheduled changes to the relay route, Metropolitan Police said. Thirty people have been arrested.