By Joe Bavier and Loucoumane Coulibaly
ABIDJAN (Reuters) - Violence erupted at around 100 polling stations in Ivory Coast on Sunday as voters decided whether to approve a new constitution that President Alassane Ouattara argues will ensure peace in the wake of years of political turmoil.
Elections worker Nandi Bamba was preparing to open the voting when a group of young men, some of them armed with clubs and machetes, attacked her polling station in Abidjan's Yopougon neighborhood.
"They demanded we stop working because the new constitution wasn't for the people. Then they smashed the ballot boxes, scattered the ballots. They broke everything," she said.
Under Ouattara, Ivory Coast has made an impressive recovery since a 2011 civil war capped a decade-long crisis. The International Monetary Fund projects it will be Africa's fastest growing economy this year.
However, despite five years of peace, Ivorians remain deeply divided along political and ethnic faultlines. And both they and the investors who are now flooding in crave the stability that will allow the world's top cocoa grower to cement its status as the continent's rising star.
Opposition parties called for a boycott of the vote, arguing that the new text was designed to further entrench Ouattara's political coalition.
Some called upon their supporters to act to stop the referendum from being held - and a low turnout could rob what is expected to be a "Yes" vote of legitimacy in the future.
Interior Minister Hamed Bakayoko said security had to be reinforced in some areas after violence erupted at around 100 polling stations in Abidjan and western Ivory Coast.
"We think there's a group going from zone to zone that is truly well organized, which has as its mission to disrupt the vote as much as possible," he said, adding that the incidents were not expected to have an impact on the result.
The current constitution, drafted under military rule after a 1999 coup, was at the heart of Ivory Coast's prolonged unrest.
In its most controversial clause, it says presidential candidates' parents must both be natural-born Ivorians - a swipe at northerners, many of whom, like Ouattara, have family ties that straddle the borders with Burkina Faso and Mali.
The new constitution scraps that rule, which was used to disqualify Ouattara from a poll in 2000, and now only one parent must be Ivorian. It also creates a post of vice president and a senate. The president says all these new measures will guarantee more political stability.
"It's an opportunity but also a duty," Ouattara said after voting in the commercial capital Abidjan. "Turning the page on the crisis born of the constitution of 2000 is essential for the future of our nation."
The new text also allows future changes to the constitution to go ahead without a referendum and with a two thirds majority in parliament - a body now dominated by Ouattara's allies.
Turnout in Abidjan was visibly lower than during last year's presidential election when 54.6 percent of eligible voters cast ballots, a fact that opposition leader Pascal Affi N'Guessan said demonstrated the text's rejection by the people.
"Either he withdraws the proposed constitution and sets up a commission in which all Ivorians can participate and write a new, more consensual constitution, or he assumes the consequences of his policies and resigns," he said.
The process of drafting the text and submitting it to a plebiscite was criticized by some civil society groups and diplomats as rushed and lacking transparency. Voters have had just two and a half weeks to review the 184-article charter.
"I'm not voting," said a woman cooking at a roadside open-air restaurant in Abidjan's Cocody neighborhood, who declined to give her name. "In just two weeks people are supposed to understand and vote on a constitution? They're imposing this."
(Additional reporting by Ange Aboa; Writing by Joe Bavier; Editing by Alison Williams)