NAIROBI-Deputy President William Ruto is edging ahead of his main rival Raila Odinga in Kenya’s presidential election, partial official results showed on Sunday, underscoring the tight race as the country anxiously awaits the final outcome.

Ruto scored 51.25 percent of the vote, reversing earlier gains for Odinga, who had 48.09 percent, according to figures from the Independent Electoral and Boundaries Commission, which has tallied results from nearly 50 percent of constituencies.

Kenya, East Africa’s wealthiest nation, held presidential, parliamentary and local elections on Tuesday.

Ruto and Odinga are in a tight race to succeed President Uhuru Kenyatta, who has reached his two-term limit. Kenyatta fell out with Ruto after the last election and has endorsed Odinga.

Election commission chairman Wafula Chebukati blamed the delay on party agents, who are allowed to scrutinize results forms before they are added to the final tally.

“Agents in this exercise cannot proceed … as if we are doing a forensic audit,” he said on Friday.

“We are not moving as fast as we should. This exercise needs to be concluded as soon as possible.”

Representatives of Odinga’s and Ruto’s coalitions did not immediately respond to requests for comment.

Media outlets have been tallying results forms from 291 constituencies posted on the election commission website.

After the forms are uploaded to the commission’s website, Kenyan election law requires that they are physically brought to the national tallying center, where party representatives can examine them for any discrepancies.

The winning candidate must receive 50 percent of the national vote plus one, and at least 25 percent of the vote from 24 of 47 counties.

The commission has until Tuesday to declare a winner.