Social media platform X said on Thursday it would work with Pakistan's government "to understand its concerns" after authorities insisted an ongoing two-month ban was based on security grounds.

The platform, formerly known as Twitter, has been rarely accessible since 17 February, when jailed former prime minister Imran Khan's party called for protests following a government official's admission of vote manipulation in the February election.

"We continue to work with the Pakistani Government to understand their concerns," X's Global Government Affairs team posted, in their first comments since the site was disrupted.

The Interior Ministry on Wednesday said X was blocked on security grounds, according to a report submitted to the Islamabad High Court where one of several challenges to the ban is being heard.

On the same day, the High Court of the southern Sindh province ordered the government to restore access to social media platform X within a week.

"The Sindh High Court has given the government one week to withdraw the letter, failing which, on the next date, they will pass appropriate orders," Moiz Jaaferi, a lawyer challenging the ban, told AFP.

The court's decision has yet to be published.

"The court order gave the government one week to decide what it wants to do," lawyer Jibran Nasir, another petitioner, told AFP.

High court orders apply provincially, but can act as a precedent for other top courts. 

Both the government and the Pakistan Telecommunication Authority (PTA) had for weeks refused to comment on the outages.

"It is the sole prerogative and domain of the federal government to decide what falls within the preview of terms of 'defence' or 'security' of Pakistan and what steps are necessary to be taken to safeguard National Security," said the interior ministry's report, submitted by senior official Khurram Agha.

The interior ministry suggested intelligence agencies were behind the order.

The closure of a social media service "when there is request from any security or intelligence agency" is "well within the scope of provisions of the PTA act", the report said. 

Digital rights activists, however, said it was designed to quash dissent after February 8 polls that were fraught with claims of rigging.

Access to X has been sporadic, occasionally available for short cycles based on the internet service provider, forcing users to use virtual private networks.

Mobile services were cut across Pakistan on election day, with the interior ministry also citing security reasons.

It was followed by a long delay in issuing voting results, giving rise to allegations of tampering.

Khan's opposition party had already faced heavy censorship in the weeks before the election, banned from television channels and from holding rallies, forcing its campaign online.

Despite the crackdown, his party won the most seats but was kept from power by a coalition of rival parties that had the backing of the military.