The swift announcement that Omar's longtime deputy, Mullah Mohammad Akhtar Mansour, would be the new leader has riled many senior figures angry about the implication that Mansour covered up Omar's death for more than two years.

The infighting could split the Taliban and threatens  tentative peace talks with the Kabul government to end 13 years of war that began with a US-led campaign after the September. 11, 2001, attacks on the United States.

Since Mansour's appointment was announced by the Taliban leadership council based in Quetta, Pakistan, it has been denounced by several top members of the group, including Omar's own brother.

Today, Taliban official Syed Mohammad Tayab Agha announced he was stepping down as director of the Political Office in the Qatari capital Doha, originally set up to enable the Taliban to negotiate in any peace process.

Agha said he considered the decision to conceal Omar's death - generally attributed to Mansour - a 'historic mistake by the individuals concerned'. "Now, as the leader is appointed outside the country and from the people who are residing outside the country is also considered as a great historical mistake," he cited in a statement.

Agha said previous leaders appointed outside the country going back to the invasion by Soviet forces, and the government set up after the Taliban were ousted, had 'very bad repercussions'.

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