imfai impact of the blast. the platform outside filled with smoke splattered with blood and the casualties strewn around. an appalling incident. 11 people killed. 39 injured. six of them in critical condition according to authorities. so the final casualty figure, the death toll could well rise in the hours ahead. an investigation is under full work now with russian prosecutors on the scene. not just at this metro station but elsewhere as well gathering what evidence they can and trying to piece together what exactly it was that took place, who planted this device and where those -- that individual or those individuals are now. so i expect there will be huge effort into this investigation. some of the witness reports that having coming from the scene absolutely harrowing. one person talking to russia media saying people were bloody. they came out of the carriage with their hair burning.