Polls re-opened Monday morning in Rome for the second and last day of the Italian capital's mayoral elections - a runoff between centre-left candidate Francesco Rutelli and his centre-right rival, Gianni Alemanno.
Polls opened at 0500 GMT and were scheduled to close at 1300 GMT with results expected in the evening, dpa reported.
When polls closed on Sunday after the first day of voting, some 1.1 million Romans, or 47 per cent of those eligible to vote, had cast their ballots.
The turnout was 10 per cent lower than on the first day of the first round of the elections, which were held on April 13-14 together with Italy's parliamentary polls.
In the first round Rutelli won 47 per cent of the vote while Alemanno won almost 41 per cent, with the remainder going to other candidates. With no candidate managing to win a clear 50 per cent majority a run-off between the top two was made necessary.
Democratic Party candidate, Rutelli, a culture minister in outgoing Prime Minister Romano Prodi's government who served as Rome mayor from 1993 to 2001, is backed by a coalition including Communists and Greens.
Alemanno, an agriculture minister in Berlusconi's last government in 2006, is running for the prime minister-elect's People of Freedom Party.
Security issues have dominated the campaign with Alemanno accusing the centre-left which has governed the city since 1993 of failing to curb crime.
He has repeatedly cited as an example the rape and stabbing of a female student from Lesotho, allegedly by a Romanian man, near a suburban Roman train station last week.
The attack is similar to the murder of a housewife in November 2007 in which the suspect, also a Romanian man, attacked his victim near another suburban train station.
The run-off is expected to be a close affair with the candidate for the hard-right La Destra party, Francesco Storace, who won some 3 per cent of votes in the first round, telling his supporters to vote for Alemanno this time.
Rome's mayoral seat became vacant when Walter Veltroni resigned last month to contest the national election as the centre-left Democratic Party's candidate for prime minister. The election was won convincingly by Berlusconi and his centre-right allies.
Veltroni had won a second term as Rome mayor in 2006 with a crushing 61 per cent of votes against Alemanno's 37 in the first round.
Also on Monday, run-off mayoral elections were being held in other Italian towns and cities including Massa Carrara, Pisa and Viterbo in the centre, and Udine and Vicenza in the north.