An unexpected surge in voters in the primaries for Kenya's ruling party overwhelmed authorities and led them to partially cancel the vote, the President announced on Saturday.

President Uhuru Kenyatta said large voter turnout sparked chaos and confusion during voting on Friday, leading to a shortage of voter materials.

"Primaries usually do not experience the kind of turnout we saw yesterday," Kenyatta said at a press conference.

His Jubilee Party took the "unprecedented and difficult decision to cancel the entire nominations exercise, because doing anything to the contrary may have resulted in a subversion of the democratic will of the people," the president said.

Protesters blocked streets and alleged rigging in the election. They voiced fear. Police used tear gas and fired shots into the air to disperse crowds at some places on Friday, newspaper "Daily Nation" reported.

Primaries in all 21 counties scheduled on Friday were cancelled - and it was unclear whether voting would proceed in the remaining 26 counties scheduled for next week. The country's general elections are scheduled for August 8.Kenyatta said the cancelled primaries would be rescheduled shortly.

More than 1,200 people were killed in ethnic clashes after an election in 2007.

Electronic tallying equipment failed in the country's most recent election in 2013, stoking voter concerns of fraud. The opposition took its complaints to the Supreme Court and several people died in protests.

The opposition alliance, known as NASA, was also holding polls this month but had staggered them over two weeks.

aw/bw (dpa, Reuters)