Human Rights Watch, in a 58-page report, said there's been limited progress in addressing a legacy of human rights abuses in Kenya. Political violence in the country has led to recent clashes that left hundreds of people dead.
Daniel Bekele, director of African programs at the rights group, said the government hasn't addressed outstanding issues that have lead to violent political confrontations in the past.
"Violence is not inevitable but the warning signs are too bright to ignore," he cautioned ahead of the vote.
The International Criminal Court last year charged four high-ranking Kenyan officials with crimes related to conflicts that erupted after disputed 2007 elections. More than 1,000 people were killed in fighting then between supporters of incumbent President Mwai Kibaki against those of rival Raila Odinga.
Deputy Prime Minister Uhuru Kenyatta and former Education Minister William Ruto were among those charged by the court. Both men said they plan to run on the same ticket with Kenyatta vying for the presidency.
"Now is the time for Kenya's international partners to help it fulfill its responsibility to protect its population," said Bekele. "The United Nations, African Union, and Kenya's allies should help Kenya prevent violence, and be prepared to respond if those preventive efforts fail."