Defeated Kenyan presidential candidate Raila Odinga has said he will seek peaceful ways to end a row over poll results, which gave a narrow first round victory to rival Uhuru Kenyatta.
Odinga said he accepted the court verdict because he wanted to avoid bloodshed, reports BBC News.
But two people died and 11 were hurt as Odinga supporters clashed with police in his western stronghold of Kisumu. There was an angry mood in the Nairobi slums of Kibera, and police briefly used tear gas to chase away protesters outside the courthouse.
Tensions were reported in another slum, Mathare.
The presidential, legislative and municipal elections held on March 4 were the first since the 2007 poll.
Official results said Kenyatta beat Odinga by 50.07 percent to 43.28 percent, avoiding a run-off by just 8,100 votes.
Kenyatta and his running mate, William Ruto, are expected to be sworn in as president and vice-president on April 9. But they are facing trial on charges of crimes against humanity at the International Criminal Court (ICC) for allegedly fuelling unrest after that election. They deny the charges.
International observers said the poll was largely free, fair and credible, and that the electoral commission had conducted its business in an open and transparent manner.