From AP via CTV.ca:

Afghanistan's interior minister says there may be between 10,000 and 15,000 Taliban fighting inside his country, and the insurgent group is operating across about 17 provinces.

Mohammad Hanif Atmar offered a rare estimate of the size of his government's most organized and potent opponent during a visit to Washington.

So, the Afghan government has released information about something secret!

To get my reference, check out this Sept. 2, 2008 post: Taliban numbers probably up: former Cdn. ambassador to Afghanistan.