Abdullah Abdullah, the main challenger to Hamid Karzai, Afghanistan's incumbent president, has threatened to boycott the runoff vote if the conditions he has set are not met.

He issued what he called minimum conditions for the runoff following the disputed first-round vote and set Saturday as the deadline for authorities to implement them.

His campaign is to announce his decision on Sunday, just days before the scheduled November 7 vote.

Al Jazeera's Jonah Hull reports from Kabul on the uncertainty gripping the runoff.