Iranian authorities have restored blocks on Facebook and Twitter after filters were removed from the social networks overnight.
Iran's semiofficial Mehr news agency quoted Abdolsamad Khoramabadi, who is a senior member of the board overseeing the Internet in Iran, as saying the filters' removal had been caused by what appeared to be a technical failure.
Khorambadi said the glitch was quickly rectified.
Newly elected President Hassan Rohani has pledged more outreach to the West and a new openness in Iran.
The glitch could point to increasing internal struggles between groups seeking to reopen Facebook and other social-networking sites and hard-liners in the establishment, who remain in control of Internet access.
In recent weeks, several Iranian cabinet members have joined Facebook, sparking a debate over its blocking.
With reporting by AFP and Reuters