Islamabad:
Pakistani authorities today briefly blocked access to Twitter on the ground that it was being used to promote a contest on Facebook for blasphemous caricatures of Prophet Mohammed before Prime Minister Yousuf Raza Gilani stepped in to end the ban.
The Information Technology Ministry said Twitter was blocked for publicising "blasphemous and inflammatory content".
Calls for participation in the contest for blasphemous caricatures were being made on Twitter, the ministry said.
The ministry said Twitter was blocked after it failed to respond to several requests from Pakistan for taking action against blasphemous content.
The ministry claimed it had contacted Twitter several times on fax but the site's administrators had failed to respond.
Late in the evening, Prime Minister Gilani's daughter Fiza Batool Gilani announced on Twitter that the ban had been lifted.
"The Prime Minister has ordered the IT Minister to restore Twitter service in Pakistan," she said in a message.
Fiza Batool, who is the government's goodwill ambassador for women's empowerment, said in another tweet that she was with the premier when the order for ending the ban was issued.
Twitter was blocked several hours after Interior Minister Rehman Malik claimed in a tweet that no restrictions would be imposed on the popular micro-blogging site.
"Dear all, I assure (you) that Twitter and (Facebook) will continue in our country and it will not be blocked.
(Please) do not believe in rumours," Malik said in his tweet.
Users from across Pakistan reported that they were unable to access the site on their computers and mobile phones since afternoon.
The Pakistan Telecommunication Authority blocked access to Twitter directly without notifying Internet Service Providers, said Wahaj-us-Siraj, convener for the Internet Services Providers Association of Pakistan.
On Saturday, TV news channels had quoted Information Technology Minister Raja Parvez Ashraf as saying that the government could restrict access to Twitter and Facebook as the sites were being used to circulate blasphemous caricatures.
The blocking resulted in many users of Twitter turning to Virtual Private Networks and mobile phone apps to circumvent the ban.
Many users poked fun at the government's crackdown and made Information Technology Minister Ashraf and Interior Minister Malik the butt of jokes.
Shortly after Malik tweeted a message while the ban was still in force, journalist Zeb Aslam posted on Twitter: "Uh...isn't it illegal for @SenRehmanMalik to be tweeting while Twitter is blocked?"
In 2010, the Lahore High Court was ridiculed by internet users and commentators after it briefly banned Facebook over blasphemous caricatures of Prophet Mohammed.
Civil society and rights groups and activists have made use of Twitter in several recent campaigns.
The government recently dropped plans to acquire sophisticated equipment to block and monitor websites after a campaign on Twitter and several other websites.
An estimated six million people use Twitter in Pakistan.