Confusion surrounds death of Nato and Afghan troops After a short conversation took place between ANA and coalition personnel, firing occurred which resulted in the fatal wounding of a [coalition] soldier and the death of his civilian colleague. In an ensuing exchange of fire three ANA personnel are reported to have died. We deeply regret the loss of life in this tragic incident. He added that investigators were trying to establish whether "the initial exchange of fire was provoked by insurgent firing." Afghan officials in Wardak gave contradictory accounts of what had happened, but one suggested a rocket or mortar had landed close to the American position. The Americans thought the shot had come from the Afghan unit and opened fire on them. Another said Afghan soldiers had opened fire on the Americans because they objected to them searching women at the checkpoint. Gen Zahir Azimi, spokesman for the Afghan Ministry of Defence, would only say the deaths had been triggered by a "misunderstanding." The American Marine commanding the coalition, Gen John Allen, said the insider attacks made him "mad as hell." He told CBS's 60 Minutes: "We're willing to sacrifice a lot for this campaign, but we're not willing to be murdered for it." One in six of all Nato deaths now comes from an insider attack. Investigations have found evidence of Taliban infiltration or coercion in only a quarter of the killings. Most others are put down to grievances and cultural clashes flaring into violence. Joint operations between foreign and local troops were dramatically scaled back a fortnight ago amid concern that an anti-Islam film made in America would provoke more Afghan troops to kill. Routine joint patrols were cancelled and any coalition operation below battalion level had to have permission from a general to work with Afghan forces. Pentagon officials said last week that the new rules remained in force, but more joint patrols were being authorised. Numbers remained far short of previous levels though.