Correspondents say the Taliban is striving for greater unity
A new chief spokesman for Taliban militants in Pakistan has been named following the capture on Monday of Maulvi Omar, Taliban officials say.
Spokesman Muslim Khan is to replace Maulvi Omar, who was arrested while travelling near the Afghan border.
Meanwhile a senior Taliban commander says he has taken over leadership of the Pakistani Taliban umbrella organisation on a temporary basis.
Maulvi Faqeer told the BBC he was now acting chief of Tehrik-e-Taliban.
He said he was just replacing Baitullah Mehsud for a short time because he was sick. Mr Mehsud was reported to have died in an American drone attack earlier this month.
But under questioning on Tuesday, Maulvi Omar confirmed that that Taliban leader Baitullah Mehsud had been killed, the Pakistani authorities say.
A Taliban official said Muslim Khan had been appointed with immediate effect.
The BBC's Syed Shoaib Hasan in Islamabad says his nomination appears to be an effort by the Taliban to create more of a unified structure in Pakistan.
Mr Khan is from the Swat valley, where militants have been under intense pressure recently because of advances by the Pakistani army.
Our correspondent says there has been tension in recent weeks between Taliban groups who have borne the brunt of the military's offensive in Swat and elsewhere in the north-west, and militants in North and South Waziristan who have so far not been seriously affected by the fighting.
The announcement of Muslim Khan's appointment was made by Maulana Faqir Mohammed, the head of the Taliban in Bajaur, another area that has seen heavy fighting.
Pakistani intelligence officials have been questioning Maulvi Omar since he was arrested on Monday in Mohmand tribal area while travelling to South Waziristan.
Footage reportedly showing Maulvi Omar being arrested
Observers say that while Maulvi Omar was never a military commander, as a senior and trusted associate of Baitullah Mehsud, he would have been able to tell his interrogators much about Taliban plans and strategy.
Mr Omar was the second prominent Taliban figure to be arrested in 24 hours.
Qari Saifullah, a commander affiliated to Harkat Jihad-e-Islami, was detained while being treated at a private hospital in Islamabad, officials said, reportedly after being wounded in a missile strike.
Both men are still being questioned about their possible roles in militant attacks in Afghanistan and Pakistan, police said.
Mr Omar was the official spokesman for Tehrik-e-Taliban Pakistan (TTP) - an umbrella organisation of regional and tribal-based Pakistani militant groups - and is said to have been a senior aide of Baitullah Mehsud.
Correspondents say his arrest is significant because he had been acting as a liaison between the various Taliban groups and was a key figure in Taliban propaganda campaigns.
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