Officials urged voters not to be intimidated by the violence amid fears the impending election results could spark another round of the ethnic-related bloodshed in which more than 1,000 people died after the 2007 vote.

The election is the first presidential poll under a new constitution designed to prevent the ethnic violence of 2007-08. Enthusiastic voters formed long lines around the country, and election officials estimated turnout at 70 percent of 14 million registered voters.

The voting got off to a bloody start when a group of 200 separatists set a trap for police in the coastal city of Mombasa in the pre-dawn hours, Inspector General David Kimaiyo said. Four police were hacked to death with machetes, coast police boss Aggrey Adoli said.

The separatist group — the Mombasa Republican Council — had threatened election day attacks, and Kimaiyo said police 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 fueled 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. An Associated Press reporter visited a morgue and saw four dead young men wearing red bandanas — a sign of the MRC — who had been shot to death.

An AP tally of the violence found that four police and three MRC members died in Mombasa, while six government officials, four MRC members and two civilians died in the three attacks near the coastal city of Kilifi, all according to police and mortuary officials.

After the polls closed, gunshots and an explosion rang out in the city of Garissa, near the Somali border, as gunmen stormed two polling stations, said Farah Maalim, the deputy speaker of parliament. Security forces responded to the attack and the gunmen fled.

The violence in the Mombasa and Garissa areas 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. Deputy Prime Minister Uhuru Kenyatta said he was discouraged by the news but he was sure the security situation would be brought under control.

Authorities flew in an additional 400 police officers to Mombasa to increase security. The United Nations restricted the movement of its staff on the coast because of the violence.

“People with ill intent must be stopped by all means,” Kimaiyo said, explaining that he directed police to use their guns to stop further loss of life, a sensitive directive given that police killed more than 400 people during the 2007-08 postelection violence.

Police said the MRC was trying to suppress voter turnout, but the long lines seen across the country also formed in Mombasa.