Both services were flowing to Iranian citizens on Monday, but officials there said the temporary reprieve was due to a technical glitch, according to The New York Times.
Facebook and Twitter are back to being persona non grata in Iran.
The tap was turned on for both social networks on Monday, raising hopes that the government had decided to loosen its blockade on the popular sites. But Iranian officials claimed that a technical problem temporarily freed up both sites, The New York Times has reported.
As of Tuesday, the blockade is back on.
Was it really just a glitch? Insiders say the problem may have been the result of a battle between different groups inside Iran, the Times noted. One group seeks to free up access to the Web, while a more hardline faction wants to continue to prevent citizens from viewing many sites.
Several Iranian officials have actually embraced social networks. Current President Hasan Rouhani has his own Facebook page and has encouraged his cabinet members to set up a social presence on the Web. Rouhani has attempted to appear more progressive than predecessor Mahmoud Ahmadinejad by promising to free up Internet access. But the hardliners continue to hold a tight rein.
Gholam Hossein Mohseni Ejehei, Iran's head of the supervisory board on Internet content, recently told the Associated Press that "it is not the time for lifting filters" on Facebook and other sites.