A helicopter crashed into a crane near a railway station in central London during the morning rush hour on Wednesday, bursting into flames and throwing plumes of smoke into the air.Police said it was too early to say if there were any casualties."It appears a helicopter was in collision with a crane on top of a building," London police said.Sky News said one pilot was on board the helicopter when it hit the crane on a building site near Vauxhall train station, a major commuter station on the south side of London, shortly after 0800 GMT.Sky reported that two cars were involved in the incident. TV footage showed flaming wreckage strewn across a road."You can see smoke billowing out just past the bridge," Robert Oxley, who witnessed the incident, told Sky News.London City Airport said flights had been disrupted on Wednesday due to low visibility. British police said there was nothing to suggest a terrorism link to the helicopter crash."There's nothing in our world at this stage," a spokesman for London's Counter Terrorism Command said. "There's nothing to suggest any terrorism link."