Iran restored access to Facebook yesterday, after a block on the social networking website last week generated accusations that the government was trying to muzzle one of the main presidential campaign tools of the reformist opposition.

Facebook was cut off Saturday, depriving challengers to President Mahmoud Ahmadinejad of a critical means of reaching out for the youth vote in the June 12 election.

The main pro-reform candidate, Mir Hossein Mousavi, is seeking a strong turnout from young voters and has used Facebook to try to mobilise support.

Authorities have not directly commented on the Facebook outage, and the reason for its return yesterday was not immediately clear.

It also was not known whether the renewed Facebook access is permanent. Iranian authorities have restored then reimposed blocks on websites in the past.