* Ukrainians set to elect new president on Sunday
* Fear of violence could deter people from voting
* Putin says Russia will respect election result
By Gabriela Baczynska
MARIUPOL, Ukraine, May 24 (Reuters) - Election officials in the southeastern Ukrainian town of Mariupol, sitting in a region where separatists have proclaimed their own "people's republic," prepared for Sunday's presidential election amid concerns that fear of violence could deter people from voting.
Armed separatist militia set up barricades of concrete, sandbags and steel pipes to protect their headquarters less than 500 metres from an election commission office in the city of 500,000 people on the Azov Sea.
Victor Kovba, the head of district election commission number 59, said 10 percent of the 100 polling stations initially set up in his area would probably remain shuttered on Sunday after being targeted by separatists.
"It's very easy to undermine an election. It's enough they would come in and mess around in three polling stations and the whole city would know immediately and people would not come in to vote," he said.
In a school on the outskirts of Mariupol, election officials had only begun setting up voting facilities on Saturday afternoon.
"We were only given this place last night. We were afraid of attacks if we set it up in advance," said the head of the station, Ina Odnorug. "We are getting ballot sheets only tonight so they are not destroyed or taken away."
Kiev hopes the elections, in which confectionary magnate Petro Poroshenko is a front-runner, will help bring stability to the country after six months of unrest during which Russia annexed Crimea.
The interim government has said the election will anchor Ukraine with the West, in defiance of Russian intimidation. Russian President Vladimir Putin said he would respect the outcome of the vote.
At least 20 people have been killed in recent days and pro-Moscow separatists said they would not recognise a vote organised by authorities in Kiev they say seized power in a coup.
SUPPORT FOR REBELS
In many places around the industrial Donetsk region, which includes Mariupol, voting is unlikely to take place.
Andrei Borisov, a young bearded man in camouflage fatigues and flak jacket carrying a machinegun, introduced himself as Mariupol's military commander for the "Donetsk People's Republic".
He said his men would not interfere with anybody who wanted to vote.
"It's the right of every person to vote and we are here to fight for the rights of the people," he said. But he said the May 11 election held by separatists, in which the region voted for self-rule, "showed how many people support us".
Neither Kiev nor the West recognised the separatist referendum and the Ukrainian government is now running a military operation in the east hoping to quell the rebels before Sunday's election.
The European Union has said it will step in with economic sanctions against Moscow if the elections are disrupted.
Ukrainian troops have set up a roadblock outside Mariupol after Borisov, the military commander, said he was determined not to let them inside the city.
"I don't want to draw blood, I just want them to go away," he said. "We didn't bring the war to them, it's them who came to kill us."
In spite of daily deadly clashes between pro-Ukrainian forces and separatist units, people crowded a Mariupol beach on Saturday to swim and soak up the sun.
Maria, sitting on the beach with her child, said however she was not going to risk venturing out to vote on Sunday. "We will stay home all day on Sunday. Going to any election is just dangerous," she said. (Editing by Angus MacSwan and Lynne O'Donnell)