A number of web users in Iran reported late on Monday that they could access Facebook and Twitter without restrictions, raising hopes that the authorities have finally lifted the filtering on the social networks.

It was not immediately clear whether Iran had in fact permanently unblocked access to the both websites or the opening was merely the result of service maintenance, something that has happened in the past. But recent news about the presence of Hassan Rouhani's administration online has reinforced speculation that it could be different this time.

"I can access Facebook and Twitter both without VPN," a citizen of Tehran told the Guardian, referring to virtual private networks used to bypass online censorship. But many other users said they still had problems connecting without help from proxy websites or VPN services.

Many users, conscious of their previous experiences, were cautious to celebrate prematurely, but others were already greeting each other. "God has freed Facebook," many posted on their Facebook pages.

Iran's president has taken a softer line on social networking websites, having described Facebook as a welcome phenomenon. He has also publicly expressed views against web filtering, which, he has said, was futile.

"In the age of digital revolution, one cannot live or govern in a quarantine," he told Chelcheragh, a popular youth magazine, before assuming office.

In recent weeks, Rouhani's cabinet ministers challenged online censorship in Iran by embracing social networks. An increasing number of officials have become active online, including the foreign minister, Mohammad Javad Zarif, whose Twitter account was verified last week. Zarif's Facebook page was hacked last week, with the intruder posting a pro-opposition Green movement status. The Iranian oil minister, Bijan Zanganeh, is also on Facebook.

"Hello world, we are tweeting without restrictions from Iran," tweeted Thomas Erdbrink, the New York Times correspondent based in Tehran. "The way Iranians are celebrating open use of Facebook & Twitter from inside the country you'd think they just won World Cup," said Iranian journalist Arash Karami in a tweet.

But Golnaz Esfandiari warned on her Twitter feed: "Don't get too excited over Facebook & Twitter accessibility in #Iran. Facebook was briefly unblocked before for state filtering to be updated."