When Internet users in Iran unexpectedly found that they could access Facebook and Twitter for the first time in over four years on Monday night, many thought the country's new president, Hassan Rouhani, may have made an official decision to remove the firewall.
However, this proved not to be the case as the government quickly moved to reimpose the blocks, sighting a technical glitch as the reason for access being granted.
"The lack of a filter on Facebook last night (Monday) was apparently due to technical problems and the technological committee is investigating this issue," said Abdolsamad Khoramabadi, who is secretary of a state committee which monitors and filters websites.
He went onto say the committee is looking into which ISPs were responsible for allowing the social media sites to be accessed.
Rouhani has promised to lighten Internet censorship a number of times since taking office at the beginning of August and some officials, including Foreign Minister Javad Zarif, have created active Facebook and Twitter profiles.
Social media sites were banned in 2009 following a series of anti-government protests which authorities said were being planned via the networks.
Many Iranians are still able to access the sites through virtual private networks (VPN), which allows users to connect through computers located outside the country. Recently the government has began to use technology that can block VPN traffic as well however.
Arash Tajik, an IT administrator in Tehran, told Reuters that he believes the temporary access might have been a government trial.
"They are testing what will happen if they remove the filter, and whether they can control the situation or not," he said.