Walker said he and his comrades walked more than 100 miles en route to the northern city of Konduz.

CNN: Walker: Prison uprising was 'mistake'

But a top Taliban leader who had been negotiating with Dostum for the surrender of Konduz said the rebellious prisoners were mostly non-Afghan fighters who acted on their own.

CNN: Taliban prisoner revolt crushed, cleanup begins

The Berlin agreements provide for commissions to supervise the elections, and these have been set up in the cities of Kabul, Jalalabad, Kandahar, Herat, Gardez, Konduz, Bamian and Ghazni.

BBC: Afghanistan's loya jirga