Traces of explosive have been found in the wreckage of the second of two Russian passenger jets which crashed earlier this week within minutes of each other.
Russian investigators had already announced the discovery of traces of explosives among the remains of one jet.
It supports widely-held theories that both aircraft were downed by bombs carried on board the planes by so-called 'black widows'.
They are Chechen separatist women whose husbands died fighting the Russians.
