KARACHI: Pakistan briefly unblocked access to the popular video sharing website YouTube on Saturday before Prime Minister Raja Pervez Ashraf ordered the plug be pulled again.

Ashraf had the website blocked in September after it refused to heed the government's call to remove a controversial anti-Islam video, and earlier Saturday the Pakistan Telecommunication Authority (PTA) notified all Internet companies to “immediately unblock/restore” until further orders were given.

But hours later Ashraf, after officials had said measures were being taken to filter out blasphemous material and pornography, ordered PTA to cut access.

“The prime minister has issued orders to block YouTube again,” a senior official in Ashraf's office told AFP, declining to provide more detail or a reason for the decision.

Television news reported that Ashraf issued the orders to block YouTube after it showed a report saying blasphemous content was still accessible.

Weeks of protests in Pakistan over the crudely made “Innocence of Muslims” film saw more than 20 people killed and caused serious damage in major cities.

Pakistan Interior Minister Rehman Malik earlier said on Twitter the decision to allow access again was due to huge public demand, and that the telecom regulator would install a firewall to maintain a block on unseemly content.

Internet Service Providers Association of Pakistan (ISPAK) had welcomed the announcement of a restoration.

ISPAK Convener Wahajus Siraj told AFP that when the ban first came into force, Internet video traffic in Pakistan plummeted by up to 30 percent.

He said unblocking access would be a positive step because many students and institutions “were using YouTube for education, and were facing difficulties as alternate websites were not as good”.

According to PTA there are 2.1 million Internet subscribers in Pakistan.