TEHRAN -- Facebook and Twitter were accessible to some Internet users in Tehran on Monday night without the aid of anti-filtering software, a very rare occurrence since just after the 2009 reelection of Mahmoud Ahmadinejad, when the sites were blocked to limit the opposition's ability to organize protests via social media.

In Tehran, customers of several Internet providers reported that they could access the Web sites without interruption, while others in the country were still being redirected to a page advising them that the site they were trying to reach was blocked.

A status update on one Facebook user’s page minutes after the site became accessible read, “God has freed Facebook!”

The loosening of restrictions comes just days after senior officials in the government of Iran’s new president, moderate cleric Hassan Rouhani, sent messages on Twitter congratulating Jews on the occasion of Rosh Hashanah, the Jewish New Year. Foreign Minister Javad Zarif, who began tweeting earlier this month, has had his account officially confirmed by Twitter.

The sudden accessibility was not accompanied by any official announcement. It's not clear whether the change is permanent, though Rouhani has said repeatedly since his election that the Islamic Republic’s authorities do not need to disrupt the flow of information to its citizens.

Although social media sites have become very difficult to access and their use had been made illegal in Iran, millions of Iranians are thought to be active on social media.