The government of Pakistan has restored access to Twitter, after briefly blocking the social networking site for what it labeled "blasphemous" material.

The tweets in question promoted a Facebook competition to post images of the Prophet Mohammad. It's considered offensive to Islam to publish depictions of the prophet.

The popular website was blocked for about 12 hours Sunday, after Twitter refused to remove the offensive material.

Mohammad Yaseen, chairman of the Pakistan Telecommunications Authority, said Facebook agreed to address Pakistan's concerns about the competition.

This isn't the first time the Pakistani government has blocked social networking sites.

In 2010, Facebook, Twitter, and YouTube were inaccessible for nearly two weeks, again because of what the government called blasphemous content.