Access to the popular social networking Web site Facebook is back in Iran after being blocked late last week.

Facebook was cut off Saturday, leading to accusations that authorities were trying to muzzle one of the main campaign tools of reformists opposing President Mahmoud Ahmadinejad in June 12 elections.

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

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

It also was not known whether the renewed Facebook access is permanent. Iranian authorities have restored then re-imposed blocks on Web sites in the past.

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