Zimbabweans have overwhelmingly backed a new constitution that calls for a strengthening of human rights and a curb on presidential powers, officials have said.
The country's electoral body said that 94.5% of voters cast a ballot in favour.
But, as the results were announced, African and international law organisations expressed outrage at the jailing for a third night of prominent rights lawyer Beatrice Mtetwa on charges that she allegedly obstructed justice.
"Her arrest is not just an attack on her profession but on the people of Zimbabwe who have just voted yes to a new constitution that enshrines fundamental human rights," said her lawyer, Thabani Mpofu.
A new constitution was a key demand of regional mediators who forged a shaky and acrimonious coalition between Zimbabwe president Robert Mugabe and the former opposition leader, prime minister Morgan Tsvangirai, after the last violent and disputed national polls in 2008.
All main political parties had called for a "Yes" vote in the referendum.
Judge Rita Makarau, head of the state electoral commission, said that just over three million Zimbabweans voted for the draft constitution and 170,489 voted against. Spoiled ballot papers were not factored into the final results of votes cast by less than 50% of those eligible to vote in the referendum.
The 170-page draft constitution has now to be submitted to the Zimbabwe parliament for approval, a procedural formality, before president Mugabe is asked to sign it into law.
The draft limits the future presidential office to two five-year terms, a clause that is not retrospective. Mugabe, 89, who led the nation to independence in 1980, can rule for another two terms if his party wins upcoming five-yearly parliamentary and presidential polls.
The proposed constitution sets up the first Constitutional Court on citizens' grievances and a Peace and Reconciliation Commission to investigate political violence and human rights abuses blamed mainly on Mugabe's ZANU-PF party over the past decade of troubled polling and alleged vote-rigging.