Abdullah Abdullah claims victory as Afghan election crisis deepens

Abdullah told a rally of thousands of rowdy supporters in Kabul that he would fight on to win the presidency, but he called for patience from loyalists who demanded he declare a "parallel government" to rule the country.

"We are proud, we respect the votes of the people, we were the winner," Abdullah said. "Without any doubt or hesitation, we will not accept a fraudulent result, not today, not tomorrow, never."

Before he spoke, a huge photograph of President Hamid Karzai was ripped down from the stage, underlining the boiling anger among many of Abdullah's supporters after the preliminary result in favour of poll rival Ashraf Ghani.

The election stand-off has sparked concern that protests could spiral into ethnic violence and even lead to a return to the fighting between warlords that ravaged Afghanistan during the 1992-1996 civil war.

But Abdullah called for the country to remain unified as it faces a difficult transfer of power, after Karzai's 13-year rule ends and as 50,000 US-led troops wind down their battle against Taliban insurgents.

"We don't want partition of Afghanistan, we want to preserve national unity and the dignity of Afghanistan," he said. "We don't want civil war. We want stability, not division."

Earlier, the United States issued a strong warning to Abdullah over reports that he would form a "parallel government" in defiance of the results from the run-off election, which said Ghani took 56.4 percent of the vote to Abdullah's 43.5 percent.

Any power grab would cost the country international aid, Washington said.

In the eight-man first-round election on April 5, Abdullah was far ahead with 45 percent against Ghani's 31.6 percent.

Karzai, who is constitutionally barred from a third term in office, has stayed publicly neutral in the lengthy election, but Abdullah supporters accuse him of fixing the vote in Ghani's favour.

Turnout on June 14 was more than eight million out of an estimated electorate of 13.5 million, far higher than expected -- fuelling fierce arguments about fraud from both sides.

Independent Election Commission head Ahmad Yusuf Nuristani announced the results of the run-off vote on Monday, admitting there had been fraud by the security forces and senior government officials.

Nuristani emphasised that the results would now be subject to auditing and adjudication of complaints, before the official result is released on about July 24.

"The preliminary result in no way means the announcement of the winner of the election," Nuristani said. "A change in the result is possible."

US warning over aid

Last-minute talks delayed the result announcement, but the two campaigns eventually failed to agree on a proposed fraud probe to clean out thousands of the most suspicious ballot boxes.

Ghani, who says he won fairly, is due to speak to reporters later Tuesday.

"The United States expects Afghan electoral institutions to conduct a full and thorough review of all reasonable allegations of irregularities," US Secretary of State John Kerry said in a strong statement.

"Any action to take power by extra-legal means will cost Afghanistan the financial and security support of the United States and the international community."

Abdullah said he had spoken to US President Barack Obama about the crisis, and that Kerry was due to visit Kabul on Friday.

Afghanistan's international backers have lobbied hard to try to ensure a smooth election process, but the contested outcome realised their worst fears and risks setting back gains made since the fall of the Taliban in 2001.

The deadlock has tipped politics into turmoil at the same time that the Taliban have underlined their strength with a major offensive in the southern province of Helmand.

The insurgents, who see the election as a US plot to control Kabul, threatened to target voters and violence spiked on both polling days, but there was no major militant attack.

The UN mission in Afghanistan has highlighted the risk of political tensions spilling over into tribal violence, though protests have so far been peaceful.

Ghani attracts much of his support from the Pashtun tribes of the south and east, while Abdullah's loyalists are Tajiks and other northern Afghan groups -- echoing the ethnic divisions of the civil war.

Karzai is due to hand over power at an inauguration ceremony on August 2.