According to Abd Allah Shah-Hassani, responsible for monitoring the vote in the southern province of Fars, "the supporters of certain candidates were trying to set up convoys of buses to take people from Shiraz to other constituencies."
"But the police prevented them," he added, without saying which political camp - reformist or conservative - was behind the move.
Although voters are permitted to cast their ballots in any constituency they choose, the organised movement of voters is strictly prohibited.
The elections are being organised by the interior ministry, currently under the control of reformists.
Meanwhile, Iran's reformist President Muhammad Khatami called on voters to participate massively in the elections to "create a surprise" and defy widespread expectations of a victory by religious conservatives.
"What is special with our people is that they have always surprised," the embattled president told reporters after casting his ballot in polls that even he has admitted are unfair.
Khamenei termed polling day
Earlier in the day, voting began in Iran's disputed parliamentary election on Friday, overshadowed by a ban on most reformist candidates and a crackdown on pro-reform media.
Supreme leader Ayat Allah Ali Khamenei called on Iranians to vote en masse in the elections, accusing the Islamic republic's "enemies" of trying to encourage a boycott.
"I thank God I am here and able to vote, and take part in this important event," said the all-powerful leader as he voted in his Tehran complex, just minutes after polling stations opened.
"Today is a particularly significant day, because the enemies are trying hard to stop the people from going to the ballot boxes. But the people are very wise," he said in a live broadcast on state television.
"What is special with our people is that they have always surprised"
"Nobody can stop the young people from voting," he asserted, adding that "I hope the outcome will be a good one."
Reformist lawmakers barred from running for re-election have said the ballot is rigged and they will boycott the poll.
Some 46 million Iranians aged 15 and over are entitled to vote for 290 deputies.
Islamic conservatives seemed certain to dominate the new assembly after the Guardian Council, a watchdog panel of unelected clerics, disqualified 2500 mainly reformist candidates.