Gmail appeared to be unavailable to some users in Iran on Wednesday, possibly as part of a government crackdown designed to suppress anti-regime demonstrations scheduled for Thursday.
Meanwhile, The Wall Street Journal reported Wednesday that the Iranian government said it would shut down Gmail and replace it with a national e-mail system. CNN reported that government officials were believed responsible for blocked text messages and sluggish Internet speeds in Tehran for days.
Gmail users in Iran reported to Google that they were having trouble getting to the service, Google said in a statement later on Wednesday.
"We can confirm a sharp drop in traffic and we have looked at our own networks and found that they are working properly," Google said. "Whenever we encounter blocks in our services we try to resolve them as quickly as possible because we strongly believe that people everywhere should have the ability to communicate freely online. Sadly, sometimes it is not within our control."
Gmail users were also reporting problems on the Gmail help forum earlier in the day.
"It is not a question. I am a journalist from tehran. Tonight we can't open Gmail," one person wrote.
Others reported on the site that they couldn't access Gmail for several days, and several posts referred to Buzz, a new social service within Gmail that Google launched this week. But it is unclear exactly when the posts were made because there are no time stamps. One post offers a date using the Persian calendar for the day but not the year.
One person posted a link to a site in Farsi, ITIran.com, that Google Translate translated to "Gmail being blocked by people to lead national e-mail," and that appeared to be dated Monday.
That item quotes "S. Mhdyvn, CEO of information technology," who appeared to be talking about a national e-mail system. That would appear to support the Journal report saying Iran's telecommunications agency announced a "permanent suspension" of Gmail in favor of a national e-mail service to be rolled out soon.
The Iranian government has been performing security sweeps and warning citizens not to participate in anti-government protests planned to mark the anniversary of the Islamic Republic on Thursday, the newspaper reported.
The government also has been confiscating satellite dishes and mobile phones, detaining mothers of people killed in street protests after the election last June, the report said, citing news services and opposition Web sites. It also said the government recently ordered death sentences for a group of arrested protesters, and CNN reported that journalists were being arrested.
In December, the Journal reported that family members of Iranian Americans had been arrested or questioned because of anti-Iranian government posts on Facebook by members outside the country.
In other instances, Iranians living abroad were forced to log in to their Facebook accounts or reveal passwords to government officials as they arrived at the Tehran airport and some even had their passports confiscated because of their political posts, according to the newspaper's report.
Also in December, two days ahead of anti-government protests scheduled for Student Day, Internet access to Tehran was shut down by authorities, according to Agence France Press. Student Day is the anniversary of the deaths of three student protesters by Iranian police in 1953.
Twitter was heavily used by Iranians to organize protests and share information with the outside world during the post-election unrest last summer.
Updated 3:08 p.m. PST with Google statement. Updated 2:06 p.m. PST with CNN reporting slow Internet and blocked text messages in Tehran, and journalist arrests.