With days of protests failing to budge Kenya's president, a weakened opposition said Friday it would turn to economic boycotts and strikes to keep up pressure over disputed elections.

The third, final and bloodiest day of protests saw ethnic clashes erupt a few dozen miles from the country's premier Masai Mara game reserve in Narok. Four people were killed, according to district commissioner Andrew Rukaria. Police chief Patrick Wambani said 25 others were wounded.

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The clashes pitted Masai tribesmen against ethnic Kikuyus and both groups were armed with arrows, clubs and knives, Wambani said, adding that homes and shops were burned. Members of President Mwai Kibaki's Kikuyu ethnic group have been chased en masse from the west of the country by other groups since the vote.

Elsewhere, police opened fire on protesters in Nairobi's Kibera slum, and a man and a woman were shot and killed. Skirmishes also broke out between police and thousands of demonstrators in the coastal tourist town of Mombasa, leaving one dead. And two man died of gunshot wounds at a Nairobi hospital that admitted 10 wounded in half an hour Friday afternoon.

A blood-smeared pickup truck carried the bodies of a 15-year-old girl and a young man to the hospital along with wailing relatives.

"They killed my daughter. Kibaki must die," a woman screamed in anguish. She said her daughter was washing utensils on her doorstep when police opened fire and she was hit.

Friday's deaths raised the toll to at least 22 people shot dead in the last two days.

Demonstrators in the western town of Kisumu set fire to a truck, then marched in the hundreds, pulling down telephone kiosks and bus shelters and burning tires. In Nairobi, police fired tear gas at a dozen protesters outside a downtown mosque.

Overall though, the rallies' strength had largely evaporated.

Kenya exploded in violence after the Dec. 27 election. Opposition leader Raila Odinga insists the president stole the vote, and international observers and the electoral chief have questioned the results.

As protests diminish and the days pass, Kibaki has become and more entrenched in power and looks unlikely to accede to demands he step down. His mandate, however, is thin even if the official tally were accepted.

The opposition's best hope may rest in wrangling a power-sharing agreement, which could possibly result in Odinga becoming prime minister or vice president.

Despite the flawed poll, international pressure is likely to focus on a power-sharing arrangement that leaves Kibaki as president. The U.S. and other allies consider Kenya a vital partner in the war on terrorism and a regional economic and military powerhouse whose stability has stood in stark contrast to war-ravaged neighbors like Sudan and Somalia, where Islamic extremism is rife.

More than 600 people have been killed in Kenya's election violence, according to a government commission, in the worst turmoil since a failed 1982 coup attempt.

Kenyan police released their own figures Friday, saying 510 people had been killed in the election violence, including 82 killed by police. Police, who had earlier denied charges they had killed anyone since Kenya descended into turmoil, have recently been more forthright, and critical of protesters.

The U.S.-based rights group Human Rights Watch said in a weekend statement that police were behind dozens of killings and that they opened fire on both looters and opposition protesters under an unofficial "shoot-to-kill" policy. Human Rights Watch said victims included people hit by police gunfire on the fringes of protests.

The police statement released Friday said police were dealing with "deception and manipulation of jobless people by their leaders. Some have been coached into committing crimes without the benefit of the bigger picture." It said the unnamed leaders were "exploiting ethnicity, religion and subjective politics."

Also Friday, Kenyan police said they had arrested two Germans and a Dutch national suspected of "terrorist activities." At least two had ties to Odinga.

One, Andrej Hermlin-Leder is a jazz musician married to a Kenyan who "knows Mr. Odinga, he's a supporter of Mr. Odinga" and spends a lot of time in Kenya, said opposition spokesman Salim Lone. "I am astounded by the charge of terrorist activities."

Lone said a second suspect, Dutch woman Fleur van Dissel, recently made a documentary about Odinga, which was aired on the private Kenya Television Network just days before the election. Details on the third suspect were not immediately available.

Police spokesman Eric Kiraithe said the arrests had "nothing to do with" connections to Odinga. He said the three "had footage of security installations in the country" and were detained "purely on criminal suspicion."

With the protests petering out, opposition spokesman Lone said Odinga would call for a "boycott of companies owned by hard-liners who are around Mr. Kibaki," including one of Kenya's biggest banks, a prominent bus company and a major dairy producer. Lone also said they would work with unions "to organize strikes in selected industries," Lone said. He declined to give details.

"We are completely ready to negotiate in good faith. We want peace in the country," Lone said. "Our people are suffering." Kibaki's government has made similar statements, but both sides appear recalcitrant and envoys from the U.S. and the African Union have failed to even bring Odinga and Kibaki together for talks.

The United States blamed the leaders' deadlock for the unrest. U.S. State Department spokesman Sean McCormack added Kibaki and Odinga needed to reach a political accommodation.

"We cannot have peace unless there is justice and they (protesters) are demanding justice, not violence," Odinga said Friday.