'Thirty-five hostages killed in Algerian helicopter attack on BP gas plant siege': Two Brits feared dead, but some captives including Americans and Irish have escaped Helicopters 'began strafing' complex, also killing 15 militants, claim rebelsMilitants had earlier threatened to blow up the hostages if they intervened Al-Qaeda group also demand safe passage out of facility with the hostagesTwo British nationals and Algerian are believed to have been killed in siegeBritain will allow Algeria to 'take the lead', but will consider request for helpPM Cameron: 'Extent of attack suggests considerable degree of planning'Attack was planned by 'one-eyed Islamist known as...