— Officials in the Crimean capital tried with mixed success Saturday to put a professional face on arrangements for the hastily planned referendum on joining Russia, and they shifted the tone of their message from overtly pro-Russian propaganda to messages and events that stressed the democratic legitimacy of the poll.

Jumbotron broadcasts that had been touting the glories of life in Russia all week switched to more neutral messages that called on voters to “defend Crimea” against the threat of Nazism by participating in the poll. Pictures of German World War II helmets were juxtaposed with happy images of children, flowers and butterflies.

Several people within earshot of the broadcasts said that they thought the Nazi threat was being overdone but that they planned to vote to be reunited with Russia in any case. A carpenter had constructed a long banner that passersby were signing with phrases such as “We are not anyone’s puppets, we are Titans!” and “NATO go to hell!”

“The fascism issue is a bit exaggerated, but my roots are Russian and I had a better life before,” said the banner’s maker, 39, who gave his name as Volodya. “I don’t think the Soviet Union has changed much, but the future seems clearer there,” he said. Crimean and Russian officials say the protest movement that toppled the pro-Russian Ukraine government last month was backed by fascist groups.

Meanwhile, election officials began final arrangements for the vote, setting up booths in hundreds of schools and colleges. At one school in Sevastopol, four booths had been built of crude wooden planks and draped with blue cloth for privacy. Plexiglass boxes had been placed to receive ballots, and voter guides listed income and service benefits of living in Russia. There was no material for the opposing side.

At a midday news conference in Simferopol, a senior election official denied rumors that tens of thousands of extra ballots had been prepared and said that only 1,512,000 had been printed in accordance with lists of registered voters. He said that 98 percent of polling places would be the same as in previous elections.

Asked about rumors that voting cards had been sent to dead people, the official, Mikhail Malyshev, responded: “Unfortunately, my mother died and she got one, too. These things happen, but it won’t affect the results.” He did not say when or where referendum results will be announced.

But officials at the headquarters of the Crimean Tatar minority group here said they had evidence that officials had sent voter cards to hundreds of nonexistent people at addresses in the capital and that bus loads of Russian citizens and soldiers were being sent into Crimea with Ukrainian passports to vote for joining Russia.

Crimean officials also presented a group of international observers at a press center set up for the referendum. Officials had said that 123 foreign observers from 23 countries had been registered but did not release a list of their names or countries. Most Western European countries refused to send observers, and those who appeared at the conference were mostly from Eastern Europe.

Serge Trifkovic, a Serbian-born writer and activist who lives in Chicago, led the group and delivered a ringing endorsement of the referendum, which he called “legal, legitimate, democratic and right.”

The Obama administration and its European allies have denounced the referendum as illegitimate, in part because of the widespread presence of Russian and pro-Russian security forces that have blanketed Crimea in the past several weeks. Most Western countries have refused to send poll observers.

Journalists faced a day of confusion and intimidation Saturday as they prepared to cover the referendum. In the morning, several hundred of them waited for hours outside the Crimean parliament building for press credentials, facing double lines of Cossack guards who shoved and shouted at a few who tried to slip past. Finally, everyone was told to go to another press center for the polling-day passes.

Then, at mid-evening, journalists staying at one hotel in the capital began tweeting that armed and uniformed men had taken over the premises and were not allowing them to leave or move between the lobby and their rooms. Some who asked what was going on were told by the hotel staff that it was a “terrorist military training” exercise. No one was reported hurt or detained, but news photographers at the hotel said their camera flash cards were seized and destroyed.

Carol Morello in Sevastopol contributed to this report.