NAIROBI (Reuters) - Kenya s incumbent President Uhuru Kenyatta won 98 percent of the vote in a repeated election in which an opposition boycott helped lower turnout to 39 percent, the electoral commission said on Monday. The announcement touched off small protests in a few opposition strongholds but also celebrations in pro-Kenyatta areas. Veteran opposition leader Raila Odinga said the Oct. 26 election was a farce. Civil society groups also cited problems with the vote. The violence has for the most part seen protesters clash with police but some Kenyans fear it is starting to take on ethnic overtones after two deaths in clashes between rival groups at the weekend. At least 66 people have died in overall election violence. On Monday, the U.S. ambassador said Washington was  profoundly concerned  by the outbreaks of violence since the re-run. Kenya is east Africa s richest economy and a key security ally of the West against militant Islam. It also a key regional trade, logistics and trade hub. In his victory speech, Kenyatta repeated his belief that his victory in the original Aug. 8 election was legitimate and said dialogue would have to wait if the opposition was going to lodge court cases again. The Supreme Court nullified the Aug. 8 vote on procedural grounds.  My victory today is just part of a process that is likely to once again be subjected to a constitutional test through our courts ... I will submit to this constitutional path regardless of the outcome,  Kenyatta said.   Those who are going to ask me:  Are you going to engage in dialogue?  ... Let them (the opposition) first and foremost exhaust all their constitutional options.   Kenyatta took 98 percent of the vote, results from 266 out of 291 constituencies showed. The electoral commission said 7,616,217 valid votes were cast, representing 39 percent of the 19.6 million registered voters.  Protests by Odinga s supporters prevented polling stations from opening in 25 constituencies.  The election commission said poor security prevented voting in those areas but the final announcement could go ahead as it would not  materially affect  the result.  In the pro-Kenyatta area of Dagoretti North in Nairobi, cars honked and crowds of supporters in red T-shirts ran through the streets.   I m so happy the president has got his seat back,  said Peterson Njau.  Now the economy is going to lift up again.   Another resident, Kennedy Okeyo, said he cared more about football than politics but that ethnic clashes in his home this weekend had unnerved him.   You can t get to work, and even if you get to work, you can get attacked because of who you are,  he said.  But just down the road in Nairobi s Kawangware slum, around 100 youths listening to the results on mobile phones chanted  No Raila No Peace . They lit a bonfire in the middle of the street and began taunting riot police with cries of  the people want teargas .  Earlier, police dispersed protesters there with teargas when they tried to block a visit by Interior Minister Fred Matiang i. Another Nairobi shanty town, Mathare, the scene of deadly clashes between police and protesters immediately after the August vote, was largely calm although a handful of protesters lit a small fire.  And in the western city of Kisumu, Odinga s political heartland, around 50 youths began to block the road at the Kondele roundabout, the epicenter of protests, while others banged metal poles together. But the protest was small.   What can I do? They ve already announced it. Even if I burn tires, nothing will change,  said 25-year-old laborer Kennedy Omondi as he watched young men set a barricade alight.  Odinga pulled out of last week s vote, saying the electoral commission had failed to institute reforms to forestall the kind of  illegalities and irregularities  that scuppered Kenyatta s victory in the August election.  Kura Yangu Sauti Yangu, a coalition of civil society organizations with 2,000 election observers, said there were  multiple  cases where results from polling stations differed from results on the forms posted on the election portal after last week s vote.  In a report, they supplied a photo taken by their observers of the tally sheet for Bashaal market center in Garissa. It showed 133 votes for Kenyatta while the form displayed online showed 433 votes. Another form posted on the election website, from Tumbeni primary school in Kakamega, showed four votes for Odinga and two for another minor candidate but recorded the total number of votes cast was 77 votes cast.  