Sharif's main opponent, Imran Khan, in his first public comments since Saturday's election, said his party would investigate reports of irregularities. His supporters staged protests in Karachi outside the Election Commission office and in the upscale Clifton neighborhood, demanding a new election for all of that port city's parliamentary seats. They also demonstrated into the night in Lahore.
"There was rigging in Lahore," Khan said in a video message recorded at the hospital in Lahore where he was recovering after a serious fall last week. "What happened in Karachi was witnessed by everyone."
Khan's anti-corruption campaign electrified the news media and large crowds in the weeks before the vote. But as returns trickled in over the weekend, it became increasingly apparent that his party would get only about 30 of the 272 seats in Parliament. And even the news of possible consolation prizes - having his party win control of the regional government of Khyber-Pakhtunkhwa province, and becoming the new opposition leader - was still up in the air, pending further results.
The secretary of the Election Commission of Pakistan, Ishtiaq Ahmad Khan, said that the final parliamentary count was delayed because of legal requirements for verification, and that the official results would not come before midweek. But he denied claims by some political workers that the delay would make it easier to falsify results.
"The nation should not have any doubt or apprehension regarding the results," he said during a news conference here in Islamabad, the capital. He stressed that as of Sunday night, the winners of only 44 of the 272 seats had been officially determined.
Officials in Karachi, Pakistan's largest city, said that voting there had been marred by extensive violence and intimidation on Saturday, including the forcible takeover of polling stations in some districts. They also cited the late arrival of election materials and widespread reports of fraud.
Local observer groups claimed that the Muttahida Qaumi Movement, or MQM, the political party that has traditionally controlled Karachi, often through brute force, frequently clashed with its political rivals in that city. Armed supporters of the MQM and the Pakistan People's Party were reported to have taken over polling stations in some Karachi election districts.
In particular, Imran Khan's Pakistan Tehreek-e-Insaf party, or PTI, and Jamaat-e-Islami, a political religious party, accused the MQM of extensive vote-rigging in a wealthy district of Karachi. The Election Commission said it had received complaints about seven parliamentary districts in the city.
Leaders of the Pakistan Muslim League-Nawaz, Sharif's center-right party, also made accusations of fraud in parts of the surrounding Sindh province. Sindh has long been a stronghold of the Pakistan Peoples Party, the former national governing party whose fortunes greatly shrank in this election. Still, many projections had it managing to keep its hold on the Sindh provincial government.
Meanwhile, analysts projected a commanding victory for Sharif, a 63-year-old conservative politician who was ousted by the military and sent into exile in 1999, returning in 2007 to build a new political movement.
Most predictions had his party winning more than 120 parliamentary seats, well past the
threshold of 100 that analysts said would allow him to form a government mostly on his own terms. On Sunday, he began meeting with senior party leaders about independent lawmakers and factions he could negotiate with to form a coalition government, party officials said.
Even as election officials noted a record turnout for the national vote - around 60 percent - analysts said that there were many questions hanging over an election widely celebrated as a triumphant moment for Pakistan's often-troubled democracy. This would be the first time a full-term elected government would hand power over to a fairly elected new administration.
Militant violence was a constant and terrifying presence throughout the campaign season, particularly in the northwest, where Taliban violence nearly knocked the traditionally dominant party there, the Awami National Party, off the electoral map. On Election Day, at least 38 people were reported killed in violence, including bombings in Karachi and Quetta, the provincial capital of Baluchistan.
The violence continued on Sunday. There were news reports that a bombing in Baluchistan killed at least three people and wounded dozens. And at least one person was reported to have died in a clash between rival political groups in Nawabshah, in Sindh province.
Baluchistan, which has been torn by sectarian violence and by a war between secessionists and the Pakistani military and its allies, was a particularly dark spot on the election map.
Analysts said that voter turnout in the province was very low, much of it derailed by the threat of violence. Initial projections showed Baluch nationalist parties in the lead, but it was unclear how either parliamentary or regional government seats could be determined fairly.
"Very few eyes were on Baluchistan," said Cyril Almeida, a columnist for Dawn, the country's leading English-language daily. "Nobody knows what really happened there."
One factor, Almeida said, is that the province has little sway in national politics, with just 14 parliamentary seats. Additionally, military intelligence and paramilitary forces maintain a tight lid on the province, and the news media have very little ability to report there.
Still, despite sporadic episodes of violence, the results have by and large been accepted by most political parties.
Shahid Ali Yousafzai, the head of U.N. team of election observers in Pakistan, said that the turnout of women in areas where their participation has traditionally been low, especially Khyber-Pakhtunkhwa province, had been notable.
"Even in Malakand division, where almost all political parties, including the secular parties, had banned female voting, women were able to cast their votes," Yousafzai said, adding that long lines of women voters were reported on the outskirts of Peshawar, the provincial capital.
The Free and Fair Election Network, a local monitoring group, on Sunday described the balloting as "relatively fair" in Punjab and Khyber-Pakhtunkhwa.
"The voting day went fairly smoothly by Pakistani standards," said Ameida, the Dawn columnist.