Pakistan's media regulators have blocked the social media platform X, formerly Twitter, with users across the country on Thursday enduring the sixth day of sweeping disruptions, partial and complete shutdowns.

There was no comment on the outage by the Pakistan Telecommunication Authority and government officials have not responded to repeated queries from The Associated Press for comment.

Human rights activists have demanded a full restoration of internet services and access to social media. Washington has also urged Pakistan to lift restrictions on X.

The outage was first observed over the weekend when the political party of Pakistan's imprisoned former Prime Minister Imran Khan announced protests against what it says were rigged Feb. 8 parliamentary elections.

In the vote, candidates backed by Khan, who was barred from running, won most seats but short of a simply majority needed to form a government.

Social media platforms are often used by protest organizers to spread the word about planned demonstrations.

Pakistan has witnessed an increase in political instability since the balloting. The country's elections oversight body denies charges by Khan's party that the vote was stolen. The Pakistan Tehreek-e-Insaf party said on Thursday that the restrictions on X have been placed by the authorities to suppress its voice on social media.

On Wednesday, US State Department spokesman Matthew Miller expressed concerns in a statement to reporters over the outage and restrictions on the freedom of expression and association in Pakistan.

“We continue to call on Pakistan to respect freedom of expression and restore access to a social media that has been restricted including Twitter, now known as X," Miller said. "We have and will continue to emphasize the importance of respecting these fundamental freedoms during our engagements with Pakistani officials.”

Khan's rivals, including the former premier Shehbaz Sharif, are trying to form a coalition government. Sharif replaced Khan after his ouster in a no-confidence vote in parliament in 2022. Khan has since then been convicted offences in what his supporters call politically motivated moves to keep him out of office.