The frontrunner in Kenyan presidential election Uhuru Kenyatta’s lead over his main rival Raila Odinga narrowed Friday, raising the prospect of a second round run-off.

Results from Odinga’s strongholds closed the gap, but Kenyatta could still secure more than 50 percent of the votes needed to avoid the run-off, with ballot counts yet to come in from about a quarter of constituencies, Reuters news agency reported.

By 07:20 a.m. GMT Friday, with 9,429,106 total votes tallied, from 219 out of 290 constituencies, Kenyatta had 4,769,769 votes or 50.1 percent, to Odinga's 4,132,062 or 43.4 percent, according results displayed by the Kenyan newspaper Daily Nation.

If no candidate achieves more than 50 percent of the votes the top two go to a run-off tentatively set for April.

Odinga, Kenya’s current prime minister, is the son of the nation’s first Vice-President Jaramogi Oginga Odinga. His rival Kenyatta is the current deputy prime minister and the son of first President, Jomo Kenyatta.

Kenyatta and his running mate, William Ruto, are due to go on trial at the International Criminal Court in The Hague on charges of crimes against humanity relating to their role in the riots that broke out following the disputed presidential elections in December 2007.  Both men deny the charges and have said they plan to clear their names.

More than 1,000 people died in the riots, the worst bout of violence since the nation gained independence from Britain in 1963. The government and opposition came to a power-sharing agreement in February 2008 and a cabinet was formed in April the same year.

On Thursday, Kalonzo Musyoka, Odinga's running mate, alleged that the vote count was rigged and that his campaign had evidence of ballot tampering.

The allegation came a day after the election officials said the new electronic voting system had broken down, severely delaying the counting of ballots cast in Monday’s election and forcing the tallying to be done manually.