Latif Mehsud was arrested by American forces; could be big blow to group.
NATO's secretary-general rejects Hamid Karzai's claim that troops did nothing but cause harm to Afghans.
Abdul Rab Rasoul Sayyaf and Ismail Khan is will for president and vice-president.
Abdullah Abdullah was runner up to Hamid Karzai in the 2009 elections.
Officials hope gesture will boost peace process.
Taliban claimed responsibility for attack on Amanullah Aman.
Hamid Karzai is pressing demands that the U.S. is reluctant to meet.
Election authorities began accepting Monday the nominations of would-be candidates.
Government making effort to negotiate with militants in tribal regions.
Ahmad Shah Massoud was slain two days before the Sept. 11, 2001 attacks.