Pakistani authorities lifted a ban on Twitter last night after earlier blocking it for hours.
The block came after Twitter refused to remove material considered offensive to Islam, but users in the country spent the day using the social networking site to denounce the ban and mock its ineffectiveness.
A spokesman for the Pakistan Telecommunication Authority (PTA) said Twitter was banned because it was being used to promote access to "blasphemous" material, namely caricatures of the Prophet Mohamed. Any representation of the Prophet is deemed un-Islamic and blasphemous by many Muslims.
"The website has been banned by Ministry of Information Technology and the decision was conveyed to us. There was blasphemous material on Twitter," Mohammad Younis Khan, a PTA spokesman, told the Agence France-Presse news agency. Reports said government officials had requested that Twitter remove the material. There was no immediate comment from Twitter.
It is not the first time the authorities have controlled information on the internet. Pakistan blocked access to Facebook, Twitter, YouTube and about 1,000 other websites for nearly two weeks in May 2010 over blasphemous content.
Pakistan has several million Twitter users and there is often a feisty and lively debate among tweeters. Last year, a Twitter user unknowingly broke the news of the US raid that killed Osama bin Laden.
Yesterday, while some Twitter users - like state-operated radio - were notable for their absence, the ban appeared largely ineffective or else ignored. Pakistan's ambassador to Washington, Sherry Rehman, posted several tweets until she was told she may be breaching the ban. The Pakistani novelist Kamila Shamsie, wrote: "Everyone with a Twitter account in Pakistan is tweeting about the just-implemented Twitter ban in Pakistan."
Ali Dayan Hasan, Pakistan director at Human Rights Watch, labelled the ban "ill-advised and counter-productive".
"If Pakistan is the rights-respecting democracy it claims to be, this ban must be lifted, " he said. "Free speech can and should only be countered with free speech."