Pakistan's foreign ministry Saturday said Chinese President Xi Jinping's state visit scheduled for this month had been postponed due to anti-government protests in Islamabad.

Pakistani opposition groups on Wednesday resumed talks with the government in a bid to end the political crisis rocking the country, but remained in a stalemate over demands for Prime Minister Nawaz Sharif's resignation.

The fresh talks came after days of clashes between police and club-wielding anti-government protesters left three dead and hundreds injured, raising fears of an intervention by the powerful military that has ruled Pakistan for more than half its history.

"In view of the current political situation in Pakistan, the governments of China and Pakistan have mutually agreed to postponement of the state visit of H.E. Xi Jinping, president of China, to Pakistan, which was scheduled to take place later this month," the ministry said in a statement.

Diplomats from both countries were discussing new dates for the visit, it added.

"Both countries underline that China and Pakistan are time-tested all-weather friends. Both sides attach high importance to the visit of President Xi Jinping to Pakistan, as early as possible, for promoting mutually beneficial cooperation between the two countries."

The Pakistan Tehreek Insaf (PTI) party of cricketing legend Imran Khan -- who has been leading the protests along with populist cleric Tahir-ul-Qadri -- claims that the 2013 general election which swept Sharif to power was heavily rigged.

Thousands of their followers have set up camp in Islamabad's sensitive "Red Zone" government district since August 15.

But their calls to overthrow the government have failed to galvanise mass support in the country of 180 million.

The military has issued a series of public advisories to the government in recent days on how the crisis should be tackled, leading to criticism that it is interfering.

Analysts and government figures have said the army may be using the crisis to its advantage to try to assert its dominance over the Sharif government.