A group demanding independence for the country’s coastal regions launched multiple attacks which killed 19 people.
It was Kenya’s first presidential election since more than 1,000 people died in post-election violence five years ago, and officials have been working to prevent a repeat.
A group of 200 rebels armed with guns, machetes and bows and arrows set a trap for police in the coastal city of Mombasa in the pre-dawn hours.
Four officers were hacked to death with machetes.
The rebels – the Mombasa Republican Council – had threatened election day attacks, but police said they were planning a raid “that will see the end of the MRC.”
The MRC believes Kenya’s coast should be an independent country. Their cause, which is not defined by religion, is fuelled by the belief that political leaders in Nairobi have taken the coast’s land for themselves, impoverishing indigenous residents.
In addition to the attack in Mombasa, police blamed the MRC for three deadly attacks in nearby Kilifi.
The violence in the Mombasa area is separate from the ethnic violence that could break out related to election results, and which was so deadly after the 2007 vote.
The country’s top two presidential candidates condemned the Mombasa attacks. Prime minister Raila Odinga called it a “heinous act of aggression” during a historic exercise. Rival Uhuru Kenyatta said he was discouraged by the news but he was sure the security situation would be brought under control.