Islamabad: Pakistan's government has imposed a travel ban on a leading journalist after he sparked an uproar by reporting that civilian officials had clashed with the military over its covert support for militants.

Cyril Almeida, an assistant editor at Dawn, the country's oldest and most prestigious English daily, announced early Tuesday he had been placed on the "Exit Control List".

The report published Friday prompted threats on social media and was denied three times by the office of Prime Minister Nawaz Sharif.

"I am told and have been informed and have been shown evidence that I am on the Exit Control List," he tweeted, followed a short time later by "I feel sad tonight. This is my life, my country. What went wrong."

In his report, Almeida said leading civilian officials had warned the powerful army to renounce covert support for proxy fighters such as the Haqqani network allied to the Afghan Taliban and Lashkar-e-Taiba, blamed for the 2008 Mumbai attacks -- or face isolation. 

Pakistan was left deeply embarrassed last month after it had to postpone a regional summit following the withdrawals of India, Bangladesh, Afghanistan and Bhutan.

India has sought to diplomatically isolate Pakistan following a raid on one of its bases in the disputed region of Kashmir, which killed 19 soldiers and triggered public fury.

New Delhi says the group which mounted the raid was based in Pakistan.

Kabul meanwhile accuses of Islamabad of failing to bring its influence to bear over the Afghan Taliban, whose leaders Pakistan hosts in its southern cities of Quetta and Karachi.

Citing sources present at a high-level meeting, Almeida said the civilian government had issued a blunt warning as part of a new high-stakes strategy: do not interfere with the police when they take action "against militant groups that are banned or until now considered off-limits for civilian action".

For years Pakistan has been accused of cracking down on only those Islamist groups which have turned their guns inward towards the state, while harbouring those who fight abroad for its strategic ends.

Reporting critical of the military is considered a major red-flag among the Pakistani media, with journalists at times detained, beaten and even killed.

Human Rights Watch accused the Pakistani Inter Services Intelligence agency of the 2011 killing of national security journalist Saleem Shahzad, an allegation the agency denied.

In a highly unusual move, the office of Prime Minister Sharif denied Almeida's report three times and "directed that those responsible should be identified for stern action".

The paper itself, which was set up by the country's founding father Muhammad Ali Jinnah, said it stood by the article.