So yes, much of the fuselage would have been on fire, after this intense heat-explosion. There is a video on line showing a burning aircraft descending from great altitude, but I have no idea if this video is genuine. The truth was the first casualty of this incident.
I remember that video and it is not linked to MH17 although some people claimed so. The video for reference that was used referencing to MH17
https://www.youtube.com/watch?v=6RnDhZDQwYI