Crash forensics to determine whether bomb downed Russian jet

With world powers divided over the cause of a Russian jetliner crash, much rests on forensic teams as they scour a sandy trail of wreckage almost a week after 224 people died in Egypt's worst air disaster.

Britain said on Thursday it believed Islamic State may have downed the jet, but Egypt said there was no evidence of a bomb and Russia said it was too early to draw conclusions.