By Hamid Shalizi and Jessica Donati
KABUL (Reuters) - Afghanistan's election commission said on Wednesday it had fired more than 3,000 staff accused of fraud in the first round of the country's presidential election, as it sought to quell fears that it might fail to deliver a legitimate outcome.
Afghans voted on April 5 in the first round of the election to pick a successor to President Hamid Karzai, who is barred by the constitution from standing for a third term after more than a decade in power.
The winner will take charge at a crucial time, with most foreign troops due to withdraw by the end of the year, the Taliban insurgency still raging and a pact with Washington permitting some U.S. forces to stay hanging in the balance.
Spokesman Noor Mohammad Noor said the Independent Election Commission had blacklisted the fired staff, so that they would not be hired in the second round.
"Some fraud was reported from those polling stations," he added, referring to the sites where the fired staff had worked.
Independent election monitors say many complaints were ignored in the effort to meet deadlines and the decision making process lacked transparency.
"The Complaints Commission must ensure to look into all the complaints so that the results are acceptable to all sides," said Jandad Spingar, director of the Free and Fair Election Foundation of Afghanistan.
The run-off will be held on June 14 and the results will be announced on July 22.
Both frontrunners, former opposition leader Abdullah Abdullah and ex-World Bank economist Ashraf Ghani, complain that widespread fraud undermined the first round, reinforcing concern that the loser on June 14 may reject the run-off result.
"The worst-case scenario would be if the election is both polarizing and the results are not accepted by one of the candidates and that has the potential to lead to conflict," Nicholas Haysom, deputy head of the U.N. mission, told journalists this week.
"The remedy to that is to make the election as transparent as possible."
More than 900 complaints classed in the most serious category were recorded in the April 5 vote, more than in the previous election, when more than a million votes were thrown out. Around 300,000 were excluded this time around.
Runner-up former World Bank economist Ashraf Ghani said most fraudulently cast votes were included in the final tally because of threats from rival candidates.
"Threats of violence, where the opposing team promised rivers of blood, created a chilling environment," Ghani said in a statement after the final results were released.
"Close to 800,000 votes that should have been declared fraudulent were included in the final count."
Abdullah Abdullah, who led first round results by a margin of nearly 14 percentage points, told Reuters this week that the true scale of fraud had not been revealed in order to salvage the process and give the electoral bodies a chance to reform.
"The whole process would have been questioned had we gone further...exposing the faults of the process," Abdullah said.
"Since there was a chance for the second round and for a correction of the system...we did not want to be responsible for that."
The Independent Election Commission said it was seeking to address fraud by firing the individuals responsible, but changing the structure of the process was impossible.
"To change a law, it has to go through the houses of parliament and takes at least six months," said Zia ul Haq Amarkhel, head of the commission's secretariat. "It is not possible in this short period of time."
(Additional reporting by Mirwais Harooni; Editing by Maria Golovnina and Clarence Fernandez)