Jocelyn Cockburn, a lawyer representing relatives of soldiers who died in Iraq, has said today's ruling is significant because it establishes that "the Ministry of Defence has a duty of care towards its soldiers ... and that duty of care extends to ... decisions about equipment."
She also told BBC News that some of the relatives plan to appeal the ruling that they may not pursue claims using the European Convention on Human Rights.
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The band announced at a free concert on Friday that they would take over the event's Pyramid stage on Saturday June 25.
The victims were collecting permits and escorts a day after their home town was liberated from the extremists.
Scotland Yard said the male youths will appear in custody at Westminster Magistrates' Court on Saturday.