NAIROBI (Reuters) - Kenyan opposition leader Raila Odinga said on Wednesday he would challenge last week’s presidential election result in court, calming fears that further street protests by his supporters might lead to widespread violence.

At least 24 people have been killed since the Aug. 8 vote, many of them shot by police. But while there have been scattered protests in Odinga strongholds, the demonstrations were relatively muted as supporters waited to hear what Odinga had to say.

When Odinga, a 72-year-old former political prisoner, called a news conference after days of public silence, crowds clustered around televisions and radios in the slums, falling silent as he began to speak.

“We have now decided to move to the Supreme Court,” Odinga told a bank of television cameras in the capital Nairobi. “This is just the beginning, we will not accept and move on.”

The election board said on Friday Kenyatta had beaten Odinga by 1.4 million votes to win a second five-year term. Odinga disputes that figure but has not yet provided proof of rigging.

The move to the judiciary will relieve Kenyans who feared a repeat of the violence that followed the flawed 2007 vote, when Odinga called for protests which led to a police crackdown and ethnic violence. Around 1,200 people died.

SEARCHING FOR JUSTICE

Odinga also contested - and officially lost - the 2013 election but quelled potential violence by taking his case to court. Judges ruled that much of his evidence was submitted outside time limits set by the court, which raised suspicion among his supporters of the judiciary’s independence.

Odinga acknowledged those frustrations, even as he backtracked on earlier opposition statements that going to court was not an option.

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“Our decision to go to court constitutes a second chance for the Supreme Court. The court can use this chance to redeem itself,” he said.

His announcement follows days of intense behind-the-scenes negotiations, with diplomats urging him not to call for protests. International and domestic observers have said the polls were largely free and fair.

Odinga has accused observers of supporting the government, but an international official who has been in contact with both sides in recent days said Odinga has struggled in talks to clearly make his case for fraud.

Another international observer said Odinga’s team had identified 11 polling stations where the opposition had proof of problems - far too few to overturn the results.

Odinga did not detail such allegations in his speech. Instead, he repeated accusations of police brutality, naming a baby and a young girl whose families say were killed by police during a crackdown on his supporters on Saturday.

“By going to court we are not legitimizing misplaced calls from some observers for us to concede. We are seeking to give to those who braved the long lines in the morning chill and hot afternoon ... a chance to be heard,” Odinga said.

Reaction to his decision was mixed, but in the Kibera slum, Nairobi’s largest, many expressed relief that they could get back to work.

“This decision to go to court is good. If they had not said that and told people to go back to the streets that would not have helped us,” said George Ouma, 28, a minibus driver. “Whatever the decision the court makes, that will be fine.”

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In Mathare slum, Zipporah Otieno, 52, said: “Court has never brought us good results ... It’s better for us to be on the road demonstrating than have our rights taken from us.”

MISSING FORMS

Earlier on Wednesday, the European Union observer mission, which has broadly praised the vote so far, urged the election commission to publish all remaining forms showing vote tallies on its website to ensure transparency.

Each individual polling station should have a form detailing the votes for each candidate, signed by all party observers. But Andrew Limo, an election commission spokesman, said about 2,900 of the 41,000 forms showing results at individual polling stations were not yet online.

“The timing of such information being made public is critical given that petitions relating to the presidential race must be filed within seven days of the results announcement,” the EU mission said in a statement.

Any challenge must be filed by the evening of Aug. 18.

The EU also criticized a government crackdown against a rights group and a pro-democracy organization that had publicly questioned preparations by the electoral board.

Police and tax authorities on Wednesday raided the Africa Centre for Open Governance, and on Monday issued a letter threatening to shut down the Kenya Human Rights Commission over administrative and tax issues.

Amid an outcry from the United Nations and international rights groups, the Interior Ministry later announced it was suspending the crackdown.