KABUL: Afghanistan's main challenger for the presidency Tuesday ruled out the prospect of striking a power-sharing deal with incumbent Hamid Karzai while stepping up accusations of widespread ballot-stuffing.

Abdullah Abdullah, who has accused the state of engineering mass fraud in a bid to secure Karzai's re-election, on Tuesday gathered tribal elders from the south -- which is traditionally seen as his rival's stronghold.

"I assure you that I'll not strike any deals based on your votes and your rights. I'll not strike any deal for power and position," he told reporters.

With results from nearly half the polling stations announced so far, Karzai leads Abdullah by 45.8 percent to 33.2 percent but still lacks the majority needed to avoid a second round.

Abdullah ran a campaign promising change and reform. Analysts believe Karzai is trying to shore up a coalition as wide as possible in order to rule by as much consensus as possible.

The August 20 presidential and provincial elections have been overshadowed by mounting allegations of fraud and fears that turnout was only 30 to 35 percent, and even lower in the south where the Taliban are strong.

On the campaign trail, Abdullah was accused of encouraging his supporters to take to the streets if he loses the election, but he again called for calm.

"I will defend your rights up to the last moment," he said, warning that a Karzai victory would re-elect a "corrupt" government for another five years.

"We will defend your rights through peaceful, legitimate means," he said as some of the tribesmen alleged massive fraud and threatened to wage violence.

"We want Karzai to resign. We want an interim administration and then a free and fair election," said one elder from Helmand province, Haji Manan.

"I implore military resistance. I swear to God, if an Islamic government, a religious government does not take office we're against it. The Americans are entering our houses. Our sons are being killed," he added.

There have been fears that the results could effectively divide the country. Abdullah has his powerbase in the north, among ethnic Tajiks, while Karzai is influential in the Pashtun-dominated south.

"I ask them for calm, for patience and for responsible citizenship," said Abdullah, distancing himself from more inflammatory remarks.

wm-jm/mtp Afghanistan-vote-politics AFP 010918 GMT SEP 09.