ISLAMABAD (REUTERS) - Pakistan restored Facebook, Twitter and several other social media apps on Friday (April 16) after blocking them for about five hours on security grounds amid a crackdown against a violent Islamist group, officials said.

"In order to maintain public order and safety, access to certain social media applications has been restricted temporarily," a senior telecommunications authority official told Reuters earlier, without specifying which social media.

The interior ministry said in a statement the block would last until 1500 local time (1000 GMT or 6pm Singapore time) and applied to YouTube, Facebook, WhatsApp, Twitter, Telegram and Tiktok.

"Access to social media applications has been restored," the telecom authority said in a later statement.

Pakistan said this week it had banned the Islamist group Tehrik-i-Labaik Pakistan (TLP) after the arrest of its leader sparked major nationwide protests, also fuelled by anti-France sentiment.

A second security source said that the block on social media was linked to maintaining public order as an operation was underway against the group.

"As the government announced earlier...wherever we need we will be blocking social media to crack down against Tehrik-i-Labaiak," he said, on condition of anonymity as he was not authorised to speak to media.

At least four policemen have been killed in three days of violence, according to the country's information minister.

Nearly 600 people have been wounded, with 200 in critical condition, he said.

TLP is demanding that the government expel the French ambassador and endorse a boycott of French products after the publication of cartoons in France depicting the Prophet Mohammad.

For Muslims, depictions of the Prophet are blasphemous. Some rights activists criticised Friday's social media blackout, warning it could lead to more severe curbs on freedoms.