I was about to put the same question and saw your post. I hit agree. Yes what is Guntakal-Secunderabad passenger doing in Alwal ? I doubt whether it is really Guntakal passenger. First of all there is no guntakal-secunerabad passenger. It should be GTL- KCG passenger. But then even if it was going to SC it shouldn't have gone to Alwal.
Always a chance that the media flashes the news without much attention to detail. It should have been KCG-Mirzapalli passenger or something else which shares the rake with GTL-KCG passenger.