KABUL, Afghanistan -- One of the candidates in Afghanistan's disputed presidential election Sunday released what his campaign said were recordings of phone calls in which a top election official, other election officials and aides of a rival candidate speak about stuffing ballot boxes and rigging the vote.
The release of the recordings is the latest effort by the candidate, Abdullah Abdullah, a former foreign minister and opposition leader, to cast the election as fraudulent. Since the June 14 runoff election, Mr. Abdullah has accused his opponent, Ashraf Ghani Ahmadzai, of colluding with election officials and President Hamid Karzai to steal the presidency. He says he has evidence that Ziaulhaq Amarkhil, the top election official, was conspiring with Mr. Ahmadzai's campaign. Mr. Abdullah's campaign said Sunday that it was not ready to describe how it had obtained the recordings, the authenticity of which has not been verified and which contain only parts of conversations. In one, a man said to be Mr. Amarkhil tells an election official in Faryab province that he should fire staff members who support "the other people" and replace them with Pashtuns and Uzbeks, the ethnic groups of Mr. Ahmadzai and his running mate. In another recording, the same voice, speaking to someone said to be a Ahmadzai aide, says, "I have spoken with the police chief yesterday to find out if he is on our side or their side."
The same voice is heard telling a man said to be an election official in southern Afghanistan to "bring the sheep fat and not empty," which the Mr. Abdullah campaign said is code that refers to stuffing ballot boxes. Another recording, said to be of an Ahmadzai aide, contains a similar phrase.
The election commission has said it has no knowledge of the conversations, and Mr. Amarkhil has denied being involved in any fraudulent activities. The country's intelligence agency, the National Directorate of Security, which was the focus of some suspicions about the provenance of the audio tapes, said it had no role in them.
Whether the recordings are authentic, the Abdullah campaign's allegations have intensified the political crisis at a delicate moment for Afghanistan as it tries to carry out its first peaceful transition of power and foreign forces prepare to depart. The growing shadow over the election has fanned Western fears that the biggest threat to the government is not posed by the Taliban, but by the corruption and ineffectiveness of its own officials.
Western officials and the United Nations urged all parties to avoid inflammatory statements while the allegations are investigated. "This includes rhetoric that brings back memories of tragic, fratricidal, factional conflicts in the 1990s that cost the lives of tens of thousands of civilians," said Jan Kubis, the U.N. special envoy for Afghanistan, in a statement.
The biggest fear for most Afghans and their Western backers is that the political crisis could turn bloody. While protests and demonstrations across Kabul on Saturday were peaceful, an undercurrent of violence, particularly along ethnic lines, ran through the words of those who took to the streets on Mr. Abdullah's behalf.
A spokesman for Mr. Ahmadzai suggested the Abdullah campaign's claims were dangerous in the absence of proof of the recordings' authenticity.
"We believe it is being released to create sedition, and what if it is proven wrong tomorrow?" said the spokesman, Abas Nawyan. "Who will be responsible for the consequences?"
Allegations about Mr. Amarkhil, who, like Mr. Ahmadzai, is a Pashtun, first surfaced on Election Day, when the police chief of Kabul confronted him with claims that he sent thousands of blank ballots to polling places in an effort steal the election. Mr. Amarkhil has vehemently denied those accusations, and in an interview on Saturday he said: "What I have done is respect the law. This is only propaganda."
Mr. Abdullah has called for the election commission to remove Mr. Amarkhil, who plays a central role in its operations, but the commission has refused.
Election officials said June 14 that more than 7 million Afghans voted, a figure that raised suspicions because it was larger than the number of voters in the election's first round and because of anecdotal reports of smaller crowds at polling places.