Thousands of supporters of the opposition leader Mir Hussein Moussavi marched in Tehran on Wednesday.
TEHRAN — Tens of thousands of protesters massed in central Iran again Wednesday to demonstrate against the disputed presidential election, as the government expanded its crackdown on journalists to try to block their coverage of opposition activities.
Iranian Readers: Share Your Views on the OutcomeThe protesters marched silently down a major thoroughfare, some holding photographs of the main opposition candidate in Friday’s vote, Mir Hussein Moussavi. Others lifted their bare hands high in the air, signifying their support for Mr. Moussavi with green ribbons tied around their wrists or holding their fingers in a victory sign.
The scope and description of the demonstration was provided by participants who were reached by telephone, as well as photographs taken by participants and journalists, despite warnings by the authorities against reporting on the event. All accredited journalists in Iran have been ordered to remain in their offices.
It was the fifth day of unrest since election officials declared a landslide victory for the incumbent, President Mahmoud Ahmadinejad.
The Iranian Foreign Ministry, meanwhile, summoned the Swiss ambassador, who represents American interests in Tehran, to complain of “interventionist” statements by American officials, state-run media reported. America and Iran broke off diplomatic relations after the 1979 Islamic Revolution.
President Obama said a day earlier that it would be counterproductive for the United States “to be seen as meddling.” But he has also said he was “deeply troubled by the violence” in Iran and that democratic values needed to be observed.
The Iranian Foreign Ministry officials, without being specific about which comments they were reacting to, expressed displeasure, the official IRNA news agency reported. The Canadian chargé d’affaires was also summoned.
Despite the government’s attempts to block communications among the opposition, calls for more mass defiance continued.
In a message on a Web site associated with him, Mr. Moussavi called on his supporters to rally again on Thursday, and to go to their local mosques to mourn protesters killed in the demonstrations, officially numbering seven. His call directly challenged Iran’s supreme leader, Ayatollah Ali Khamenei, who had urged Mr. Moussavi to work through the country’s electoral system in contesting the election results.
Iranians using the Internet messaging service Twitter had already spread the word about the silent demonstration Wednesday.
The sense of threat against the opposition was growing. Reuters reported that Mohammadreza Habibi, the senior prosecutor in the central province of Isfahan, had warned demonstrators that they could be executed under Islamic law.
“We warn the few elements controlled by foreigners who try to disrupt domestic security by inciting individuals to destroy and to commit arson that the Islamic penal code for such individuals waging war against God is execution,” Mr. Habibi said, according to the Fars news agency. It was not clear if his warning applied only to Isfahan, where there have been violent clashes, or the country as a whole, Reuters said.
The government’s new restrictions were directed at blocking communications between opposition supporters and any news coverage of their activities.
The Associated Press reported that the powerful Revolutionary Guards threatened to restrict the digital online media that many Iranians use to communicate among themselves and to send news of their protests overseas. In a first statement since last Friday’s vote, the Revolutionary Guards said Wednesday that Iranian Web site operators and bloggers must remove content deemed to “create tension” or face legal action, The A.P. said.
In Paris, Soazig Dollet, a spokeswoman for Reporters Without Borders, a press freedom advocacy group, said at least 11 reporters had been arrested since the elections and the fate of 10 more was unclear since they may either be in hiding or under arrest.
On its Web site, the organization said Aldolfatah Soltani, a lawyer and human rights activist, had been detained along with “10 or so opposition activists, politicians and civil society figures” in Tehran and three other cities — Tabriz, Isfahan and Shiraz.
On Tuesday, the government revoked press credentials for foreign journalists and ordered journalists not to report from the streets. On Wednesday, government officials telephoned or sent faxes to reporters in Tehran working for foreign news organizations ordering them not to venture outside to cover events being held without an official permit. That included rallies by supporters of Mr. Moussavi and news conferences or other public events held without the government’s approval, reporters in Tehran said. At least one newspaper has stopped printing.
Government officials told journalists that they were at risk on the streets following an incident on Tuesday when a photographer was stabbed and wounded while covering a rally. Two well-known analysts, Sayeed Leylaz and Mohammad-Reza Jalaipour, were detained Wednesday and were likely to be held for several days, associates and family members said.
Defying the restrictions, new amateur video surfaced outside of Iran on Wednesday, apparently showing a government militia rampaging through a dormitory area of Tehran University late Tuesday or early Wednesday.
Support for the protests came from some unusual quarters. Five Iranian soccer players, including the captain, Ali Karimi, wore green wristbands in an apparent sign of support for Mr. Moussavi at a World Cup Asian qualifying match in South Korea, The A.P. said, quoting state television.
The Fars news agency also reported that the partial recount of votes ordered Tuesday by the Guardian Council, the 12-member body of jurists which supervises elections and holds veto power over legislation in Iran, had begun. A recount of votes in Kermanshah, a Kurdish province, showed that “there has been no irregularity,” the news agency reported.
The recount, intended as a effort to meet the opposition’s concerns, has failed to halt the unrest. On Tuesday, a large protest by thousands of supporters of Mr. Moussavi stretched for miles along a major thoroughfare in Tehran. The marchers, dressed largely in black and green, marched mostly in silence, some carrying signs in English asking, “Where is my vote?”
Despite the media crackdown, extraordinary accounts about the protests in Tehran and other cities have reached the outside world. On Tuesday, many Web sites posted a wrenching video that purported to show the shooting death of a student in Isfahan in a shooting by pro-government militia members. Other videos showed limp and bleeding demonstrators in Tehran after the unprecedented protests of hundreds of thousands on Monday.
Worry over the future of Iran, a country crucially important for its oil, its proximity to Iraq, Afghanistan and Pakistan, its nuclear program and its ties to extremist groups, spilled over its borders.
In Vienna, Mohamed ElBaradei, the head of the United Nations atomic energy watchdog, said in a BBC interview that he believed Iran wanted to develop nuclear weapons technology “to be recognized as a major power in the Middle East.”