TEHRAN, Iran - The leader of Iran's protest movement accused the government yesterday of lies, fraud, and murder, while the government turned its ire on the United States, accusing the Obama administration of stirring the unrest over Iran's disputed election.

The increasingly bitter rhetoric came as supporters of Mir Hossein Mousavi defied a ban on unauthorized rallies and took to the streets again, as they have each day since the Interior Ministry declared Saturday that Mousavi lost the June 12 balloting to President Mahmoud Ahmadinejad in a landslide.

Mousavi, a former prime minister who contends he won the election, demanded that the country's legal authorities stop plainclothes police and vigilantes from attacking his supporters. In a statement on his Web site, he said the huge march Monday by hundreds of thousands of his backers - the largest unsanctioned demonstration in Iran since the 1979 Islamic revolution - had "infuriated" the government and its paramilitary forces, which he called the "Disciples of Lies."

"They tried to make bitter the sweetness of this great gathering with their beastly attacks," he said, referring to the killing of seven protesters by a government-backed, volunteer militia known as the Basij, which fired into a crowd outside its local headquarters at the end of Monday's march. Mousavi called it "an appalling murder."

He also complained about the Basij in a separate letter to Iran's National Security Council. The paramilitary organization, which has an estimated eight million members nationwide, has violated the "freedom, order and security [which] are the intertwined rights of all citizens," Mousavi wrote in the open letter, referring again to the government and its shadowy forces as the "Disciples of Fraud and Lies."

The government, meanwhile, summoned the Swiss ambassador, who represents U.S. interests in Tehran, to complain of "intolerable" interference by the United States in Iranian internal affairs, state television reported. Iranian authorities had made similar complaints earlier this week to the ambassadors of Germany, France, Britain, and the Czech Republic.

In Washington, the State Department rejected the Iranian allegation, saying the United States was in "good company."

"As the president has said, we are not interfering in the debate that Iranians are having about their election and its aftermath," State Department spokesman P.J. Crowley said. "This is not about the United States."

'Amazing ferment'

President Obama, who has come under criticism from some quarters in Washington for not speaking out directly on behalf of the Iranian protesters, said Tuesday that he hoped the Iranian government would affirm "the universal principles of peaceful expression and democracy" but that the United States was "not meddling" in the "amazing ferment taking place in Iran."

Efforts to clamp down on outside sources of information continued yesterday as authorities blocked CNN's Web site and reportedly jammed some BBC satellite television broadcasts. Cell-phone service, including text messaging, was turned off for the fifth day in a row, and social-networking sites such as Facebook and Twitter remained partially blocked.

Word of mouth is already the main way for Iranians to get information about the protests, and some Iranians said they feared that a complete shutdown of all Internet services and satellite TV broadcasts might be coming. Adding to those fears, Iranian state television aired a program, titled The Green Wave, that portrayed the protest movement as being fomented by foreign media, including the BBC and the Arabic station Al Jazeera.

'Main orchestrators'

The deputy head of Iran's National Security and Foreign Policy committee, Hoseyn Sobhaninia, called this week for steps against CNN and the BBC, whose Farsi-language satellite channel is hugely popular here. "Without a doubt, foreign media, and especially the BBC's Persian service and radio, are the main orchestrators of disorders in the country, guiding rioting elements that support neither the candidates nor the Islamic revolution," Sobhaninia said Tuesday.

Many Iranians took a break from politics yesterday to watch the national soccier team play a World Cup qualifying match in South Korea. But several of the Iranian players, including the team's captain, came onto the field wearing green wristbands in apparent solidarity with Mousavi's supporters. Some fans at the game, which was televised from Seoul and ended in a 1-1 tie, also waved banners reading: "Free Iran."

Arrests of opposition leaders continued yesterday, following a wave of detentions that began over the weekend. Saeed Laylaz, a political analyst who often gives interviews to the Western press, was among those arrested yesterday, sources close to him reported.

Yet tens of thousands of protesters poured into the streets of the capital in defiance of a ban by the Interior Ministry, which is headed by a staunch supporter of Ahmadinejad. Foreign journalists were not allowed to attend the demonstration, but witnesses and participants interviewed afterward said police officers, wearing yellow vests, stopped traffic as the demonstrators walked silently and peacefully from the central Haft-e Tir square to Revolution Street. Riot police, who have been nearly ubiquitous in Tehran since Saturday, were nowhere to be seen.

According to those interviewed, the diversity of the crowd reflected the broad movement demanding the annulment of the elections and a new round of balloting. Young women in traditional black chadors walked next to businessmen holding briefcases, while a mother pushing a baby stroller held up a placard that read "Where is my vote?" in English.