The Taliban in Pakistan are divided into different factions
A power struggle has broken out between the diverse militant factions that make up the Pakistani Taliban.
A leading militant, Maulvi Faqir Mohammad, has criticised two other Taliban members for saying that they are now leading the movement.
Meanwhile officials in the north-west say the border with Afghanistan has been closed to prevent militants from disrupting the election there.
They say the two main border crossings will remain shut until Friday.
The crossings are in the Khyber tribal region and in Balochistan province.
But there are hundreds of informal crossings, not manned by troops, along the 2,500km (1,553 miles) border between the two countries.
The BBC's Syed Shoaib Hasan says the row within the ranks of the Taliban is the latest sign of major disunity within its ranks.
Our correspondent says that the source of the disagreement is over whether or not the Taliban should officially recognise that commander Baitullah Mehsud is dead and who has officially taken over from him.
Mr Mehsud was reportedly killed in a US drone attack earlier in August. Some elements of the Taliban, however, continue to deny his death.
Maulvi Faqir Mohammad, head of the Taliban in the Bajaur tribal region, told the BBC Urdu service on Wednesday that he was now the "temporary" head of the Tehrik-e-Taliban Pakistan (TTP) organisation.
But two other militants, Hakimullah Mehsud and Waliur Rehman, have also said that they were in charge.
The organisation was formed by Baitullah Mehsud in a bid to unite all the various Taliban factions under one umbrella.
But now it appears to be disintegrating amid increasingly bitter recriminations.
Maulvi Mohammad was appointed deputy head of the TTP when it was formed, but has suffered a loss of prestige and power following the Pakistan army's operation in Bajaur.
The Taliban leadership there eventually agreed to an unconditional ceasefire following massive losses.
It accused Taliban militants in the South Waziristan tribal area of not doing enough to help them and of concentrating too much on the war in neighbouring Afghanistan.
Maulvi Faqir Mohammad said that while Hakimullah Mehsud and Waliur Rehman had the ability to lead, "the Taliban Shura has to be consulted before a final decision is reached".
He also said that he intended to change the name of the organisation to Tehreek-e-Ittehad Taliban (Movement of United Taliban).
The announcement is seen as another sign that the various Taliban factions are now openly jockeying for control of the TTP and its resources.
It could also mean the beginning of the end for Pakistan's largest militant organisation.