On Wednesday, a suicide bombing near a polling station in Quetta killed at least 31 people.
His unusual press conference at 4am local time came hours after PML-N president Shahbaz Sharif in Lahore outrightly rejected the results, alleging "blatant" rigging of the election, even though the vote count was under way. As Mike Armstrong explains, the election results could have wider repercussions for the region.
Pakistanis were voting Wednesday in a historic third straight election ending a campaign marred by widespread allegations of manipulation that local and worldwide rights group have said imperil the country's wobbly transition to democratic rule.
Pakistan Peoples Party co-chairman Bilawal Bhutto Zadari, 29, expressed similar concerns on Twitter. As many as 11,673 candidates are contesting the elections from across the country.
"The delay is being caused because the result transmission system has collapsed". Pakistan Tehreek-e-Insaf is leading in over 110 seats as the results keep trickling in.
As election workers sorted through massive piles of paper ballots, other major parties including the Pakistan Peoples Party (PPP) also alleged the count was being manipulated.
Sharif's party tops another poll with 26 percent compared to 25 percent for Khan's Pakistan Tehreek-i-Insaf (PTI).
Could Imran Khan's vote in Pakistan election be cancelled?
The military, which has ruled Pakistan for almost half of its 71-year history, denies any effort to influence the election. According to the latest opinion polls, neither Mr Khan nor Mr Sharif are likely to win a clear majority in the election.
His accusations centre on official ballot results paperwork, known as a Form-45, not being shared with his party at polling stations.
"We totally reject this result", he said.
About 371,000 soldiers have been stationed at polling stations across the country, almost five times the number deployed at the last election in 2013. Among those making the accusations was PML-N leader Nawaz Sharif, who was ousted as prime minister after a Supreme Court verdict in the Panama Papers investigation past year.
The elections are being held as emotions run over a graft case that led to the imprisonment of ousted Prime Minister Nawaz Sharif and his daughter Maryam Nawaz.
"Claims of electing rigging occur after every election in Pakistan - but this time around, they will be harder to brush aside given the overt role the military has played", said Shamila Chaudhary, a former White House and State Department official who's now a fellow at Johns Hopkins University School of Advanced International Studies. One candidate in the Sindh provincial assembly was unopposed and has already secured that seat. The election was marred by a deadly suicide attack and allegations of manipulation by the powerful military, with several parties raising objections over the entire process.
The election is considered Pakistan's second consecutive democratic transition in 71 years.
However, it still remains to be seen who manages to be the Prime Minister of the country, which has in its history of 7p years been ruled by the military for a long decade. The ECP was also criticised for deploying the Army both inside and outside of polling stations.
At least one party - Tehreek-e-Labaik Pakistan (TLP), which blockaded the capital Islamabad for weeks past year over blasphemy - has already announced they are planning protests.