text: Returning officers were ordered to physically deliver paper copies of their constituency's tallies to the counting centre in the capital.
  Election officials have urged patience.
  Uhuru Kenyatta, who faces trial at the International Criminal Court, has been leading in early presidential results declared from Monday's tightly contested election.
  He is due to stand trial at The Hague next month for allegedly fuelling violence after the disputed 2007 election. He denies the charge.
  His closest rival is outgoing Prime Minister Raila Odinga.
  With provisional results in from more than 40% of polling stations earlier on Wednesday, Mr Odinga had 42% of the vote compared with Mr Kenyatta's 53%.
  However, Mr Odinga's allies remain confident that he will gain ground as results from his strongholds, including the Coast Province, are declared.
  More than 1,000 people were killed in the violence which broke out in 2007-08 after Mr Odinga claimed he had been cheated of victory by supporters of President Mwai Kibaki, who is stepping down after two terms in office.
  The BBC's Solomon Mugera in the capital, Nairobi, says Kenyans are becoming increasingly anxious about the delay in finalising the results.
  Some businesses and schools across the country have remained shut since Monday's election, he says.
  This has led to a shortage of goods, pushing up the prices of basic foodstuff in areas such as Kibera, the biggest slum in Nairobi and a stronghold of Mr Odinga, our correspondent adds.
  Uhuru Kenyatta
  Raila Odinga
  Profile: Uhuru Kenyatta
  Profile: Raila Odinga
  Some electoral officials have had to drive hundreds of kilometres to the counting centre in Nairobi to deliver paper copies of the tally of their returns.
  At about 13:00 local time, returning officers from only 53 of the 290 constituencies had arrived and the election commission said it would announce results from constituencies as they were ready.
  Its website had stopped giving updated results from the presidential race on Wednesday, and was still showing figures from Tuesday night.
  Our correspondent says the large number of spoiled ballots - about 6% of the total vote, well over double the number of votes cast for the third-placed candidate, Musailia Mudavadi - has become a major bone of contention.
  Mr Odinga's Coalition of Reforms and Democracy (Cord) wants them to be counted, but Mr Kenyatta's Jubilee Coalition is resisting this.
  Late on Tuesday, the election commission announced that the spoiled ballots would count in the overall vote total, increasing the likelihood of a run-off between the top two candidates, news agencies report.
  Mr Kenyatta's running mate William Ruto, who is also facing a trial at the ICC, said foreign embassies may have influenced such a decision.
  "We want to believe that this is not an attempt to deny the Jubilee Coalition a first-round victory as is clearly now on the wall," he is quoted by Reuters news agency as saying.
  But the election commission now says a decision on what to do about the spoiled ballots will be taken after all other votes are counted, our correspondent reports.
  If no agreement is reached, one of the presidential candidates is bound to mount a legal challenge, he says.
  As there are different types of spoiled ballots, a possible compromise would be to include those that were annulled simply because they had been put in the wrong box - for instance, in the parliamentary box rather the presidential box - while excluding a ballot paper on which a person had voted for two candidates, our reporter says.
  In the run-up to the election, the European Union (EU) said it would only have limited contact with a president who faced trial at the ICC, while US Assistant Secretary of State Johnnie Carson warned Kenyan voters that "choices have consequences".
  The winning candidate must get more than 50% of the total votes cast and at least 25% of votes in half of the 47 counties.
  If there is no clear winner, a second round of voting will take place, probably on 11 April.
  Kenya elections: Maps and graphics
target: Counting of Kenyan election results has slowed down because of problems with the electronic systems.