Pakistani authorities say the full results of a general election will be delayed as cricket hero-turned-politician Imran Khan leads in a partial count that opponents say was rigged.

The party of Mr Khan’s jailed chief rival, ousted Prime Minister Nawaz Sharif, called the count an assault on democracy in the nuclear-armed, Muslim country that has a history of military rule.

Election Commission of Pakistan (ECP) secretary Babar Yaqoob said on Thursday that counting had been delayed by technical failures in an electronic reporting system. Tallying was now being conducted manually.

“There’s no conspiracy, nor any pressure in delay of the results. The delay is being caused because the result transmission system has collapsed,” Mr Yaqoob said.

He said he could not set an exact deadline when the full results would be released but it would be as soon as possible.

Chief Election Commissioner Sardar Mohammad Raza later defended the process after Sharif’s party and at least four others contesting the elections alleged the counting was manipulated.

“These elections were 100 per cent transparent and fair,” Mr Raza said.

“There is no stain. Why don’t you think the five political parties might be wrong?”

The Electoral Commissioner said there was no conspiracy or pressure to delay the results.

With 30 per cent of the total vote counted, Mr Khan’s Pakistan Tehreek-i-Insaf (PTI), or Pakistan Movement for Justice, was listed by the ECP as leading in 113 of 272 contested National Assembly constituencies.

Sharif’s Pakistan Muslim League-Nawaz (PML-N) was ahead in 66 constituencies, and the Pakistan Peoples Party (PPP), led by the son of assassinated two-time prime minister Benazir Bhutto, led in 39 constituencies.

Mr Khan’s camp was increasingly confident, although it still appeared likely to fall short of the 137 seats needed for a majority in the National Assembly, raising the prospect it would need to find coalition partners among smaller parties and independents.

Mr Khan’s party spokesman, Fawad Chaudhry, tweeted “Congratulations to the nation on a new Pakistan! Prime Minister Imran Khan”, although his party has officially held off on declaring victory. 

Wednesday’s voting was marred by a suicide bombing that killed 31 people near a polling station in Quetta, capital of the southwestern province of Baluchistan. Islamic State claimed responsibility.