WASHINGTON—The State Department asked the Twitter social networking site to delay scheduled maintenance earlier this week to avoid disrupting communications among tech-savvy Iranian citizens as they took to the streets to protest Friday’s re-election of President Mahmoud Ahmadinejad.

The move illustrates the growing influence of online social networking services as a communications medium. Foreign news media coverage of the unfolding drama, meanwhile, was limited by Iranian government restrictions barring journalists from “unauthorized” demonstrations.

“One of the areas where people are able to get out the word is through Twitter,” a senior State Department official said in a conversation with reporters on condition of anonymity. “They announced they were going to shut down their system for maintenance, and we asked them not to.”

Twitter did not reply to a request for comment.

In Iran, supporters of Ahmadinejad and his election rival, Mir Hossein Mousavi, massed in competing rallies Tuesday as the country’s senior Islamic cleric threw his weight behind opposition charges that Ahmadinejad’s re-election was rigged.

“No one in their right mind can believe” the official results from Friday’s contest, Grand Ayatollah Hossein Ali Montazeri said of the landslide victory claimed by Ahmadinejad.

Montazeri accused the regime of handling Mousavi’s charges of fraud and the massive protests of his backers “in the worst way possible.”

“A government not respecting people’s vote has no religious or political legitimacy,” he declared in comments on his official Web site. “I ask the police and army [personnel] not to ‘sell their religion,’ and beware that receiving orders will not excuse them before God.”

As many as three more protesters were reported killed in clashes Tuesday in Vanak Square, adding to the eight who were confirmed killed in Monday’s protests.

In an attempt to defuse the crisis, the 12-member Guardian Council, part of the ruling theocracy, announced that it would conduct a partial recount of the balloting, which the government said Ahmadinejad won with more than 24 million votes, to 13 million for Mousavi.

Ayatollah Ali Khamenei, Iran’s supreme leader, made an extraordinary appeal for calm. “In the elections, voters had different tendencies, but they equally believe in the ruling system and support the Islamic Republic,” he said at a meeting with representatives of the four presidential candidates. “Nobody should take any action that would create tension, and all have to explicitly say they are against tension and riots.”

How much twittering actually is going on in Iran itself is hard to determine. The tweets circulated by Iranian expatriates in the United States tend to be in English—the Twitter interface does not support the use of Farsi. And though many people may be sending tweets out of Iran, their use in Iran may be low, some say.

“Twitter’s impact inside Iran is zero,” said Mehdi Yahyanejad, who manages a Farsilanguage news site based in Los Angeles. “Here, there is lots of buzz, but once you look, . . . you see most of it are Americans tweeting among themselves.”

Users around the world following the election drama in Tehran found it listed as the most popular discussion topic Monday and Tuesday on Twitter. Many users, logging on from outside Iran, said they changed their account’s location listing to Tehran to confuse government censors who might be trying to shut down communications from Iran.

Since Friday, Iranian expatriates have kept each other apprised of events on Facebook by forwarding “tweets” to each other, containing information that often appeared to have originated in Iran.

“My friends are being held against their will in the university,” one wrote. “Rasoul Akram hospital has medics outside, go there for help,” another advised. Some expatriates uploaded pictures and videos of police violence against protesters to photo and video sites such as Flickr and YouTube.

Mainstream media have confirmed some information tweeted about planned gatherings, or about the shooting of a protester. Other reports have been debunked or have so far proven impossible to verify.

Though Twitter wasn’t the only Web service used by supporters of Mousavi as Iran’s election drama played out early this week, Iranian government officials were more successful in shutting out access to Web sites like Facebook than Twitter, where entries are limited to 140 characters or less.

Tech industry analyst Rob Enderle said Twitter might be more resistant to attempts to block access because users can update via a cell phone’s text-messaging service, or “short message service.”

“Twitter is a unique property because it works easily with SMS,” Enderle said. “That gives it a resiliency that isn’t shared by other online-only sites,” such as Facebook.

To block Twitter use, he said, Iran would have to shut down text messaging on a one-to- one basis, a tedious and time-intensive process, or shut down text messaging throughout the country.

“The Iranian government may eventually block it, but for now they’re apparently not set up to do that,” he said.

McClatchy Newspapers contributed to this report.