Anti-riot police took action as chaotic scenes unfolded at Kenya's national tallying centre at the Bomas of Kenya (a tourist village) late Saturday, halting the ongoing verification of presidential votes.
Allies of longtime opposition leader Raila Odinga cited alleged irregularities in the process by election officials.
Odinga's chief agent Saitabao Ole Kanchory walked to the podium and shouted into the microphone "I want to tell Kenyans that Bomas is a scene of crime," before the microphone was turned off on live television.
Kenya's hotly contested presidential vote has been marred by allegations of rigging.
By early afternoon, Odinga had 52.54 percent of the vote (2,288,315 votes), compared with 46.76 percent (2,036,795 votes) for Ruto in 29.92 percent of polling stations, according to official results released from Nairobi, where the Independent Electoral Commission (IEBC) is collecting, counting and verifying results.
Final results are due to be announced by August 16, as required by law. If neither of the two front-runners receives more than 50 percent of the vote, Kenya will have its first presidential run-off.
While Kenya is considered an island of stability and growth in the heart of a troubled region, the results of every presidential election since 2002 have been contested, sometimes violently.
Nearly a week after 22.1 million Kenyans were called to the polls, the country is still waiting to know the name of Uhuru Kenyatta's successor, who, after serving two terms since 2013, is not eligible to run for a third.