The party of Kenyan presidential frontrunner Uhuru Kenyatta described as suspect Wednesday the inclusion of a mountain of spoiled ballots in results of elections two days ago, as frustrations grew over the slow pace of the count.
Monday's elections were the first since 2007 when a dispute over the counting process erupted into weeks of deadly violence that left more than 1,100 dead.
Leaders and election officials urged calm after hitches led the electronic tallying system to stall after votes from just over 40 percent of polling stations had been counted, giving Kenyatta 53 percent of valid votes with 42 percent to his closest rival, Raila Odinga.
With the gap small enough to be overturned, the inclusion of the large number of spoiled ballots in the count was becoming a key controversy.
Spoiled ballots make up more than five percent of votes cast so far and made public.
Their inclusion was motivated by a "sinister and suspect" logic, charged an official from Kenyatta's coalition, Charity Ngilu.
"The Jubilee Coalition is scandalised that sensible Kenyans can so much as think of including condemned ballots," she told reporters.
The inclusion of so many spoiled ballots in the count greatly adds to the number of votes needed for a candidate to break the 50 percent threshold for a first round win, raising the prospect of another round due within a month.
There was also concern over the widespread failure of a system by which electoral commission had been broadcasting running tallies based on encrypted text messages received from polling stations.
After the system stalled midday Wednesday, the Independent Electoral and Boundaries Commission (IEBC) switched to reading out results delivered in person by returning officers.
With the electronic scoreboard removed, it was no longer possible to see who had an overall lead.
Helicopters and chartered planes ferried election officials from far-flung counties to Nairobi to deliver results, with others coming by road.
At the rate, publication of country-wide results could still take days.
Kalonzo Musyoka, Kenyan vice-president and Odinga's running mate, said the party was worried at the "failure of the IEBC electronic registers as well as the huge numbers of spoilt votes".
But he urged supporters to keep the peace.
Odinga, the prime minister, says he was robbed of victory in 2007 when disputed results triggered the bloody ethnic violence.
Kenyatta faces trial at the International Criminal Court (ICC) for crimes against humanity over the violence.
To win outright and avoid a second round runoff, a candidate must win "more than half of all the votes cast", according to the constitution, as well as at least 25 percent of votes in more than half of all 47 counties.
Kenya's Daily Nation warned in its Wednesday editorial that even though the elections were largely peaceful there was a potential "rocky road" ahead.
"Election-related violence last time occurred not during the peaceful voting and counting, but in protest after the announcement of suspect results following lengthy unexplained delays," it noted.
Many have complained at a lack of voter education ahead of the polls, one of the most complex Kenya has ever held with six ballots cast, including for governors.
"It's taking a long time, let's hope that they are not doing something fishy," said airport worker Jack Mwai.
The electronic systems that failed were designed to frustrate potential rigging and not major incidents have been reported so far.
Kenya has been largely calm in recent days apart from isolated incidents of violence, including clashes on the coast between police and attackers that killed 12, as well as several bomb explosions, wounding at least two.
The results of the 2007 poll, pitting President Mwai Kibaki against Odinga, sparked a wave of protests, notably over the lack of transparency in the way the votes were counted.
Odinga and his rival Kenyatta -- the son of independent Kenya's founding president as well as one of Africa's richest and most powerful men -- have publicly vowed there will be no repeat of the 2007-08 bloodshed.
But the trials later this year at The Hague-based ICC for Kenyatta and his running mate William Ruto have raised the stakes: should they win the vote, the president and vice-president could be absent for years.