Iranians took to the polls on Friday to vote in a run-off election for the remaining 68 of parliament's 290 seats, with the first results due to be announced on Saturday evening.
Some 17 million Iranians were registered to take part in the vote, according to the country's Interior Minister, which extended voting in 55 districts for two hours until 8 pm (1530 GMT).
The first round of voting in February saw a victory for reformist candidates allied with President Hassan Rowhani against hardliners. Reformists in Tehran, for example, won all 30 parliamentary seats outright.
A fundamental reason for the hardliners' electoral defeat in February was coalition talks prior to the elections between reformists and the moderate conservatives. Unlike the three previous legislative periods, conservatives decided against a coalition with hardliners.
According to observers, the run-off is unlikely to change the direction of new parliament, with the results from the first round in large cities such as Tehran and Isfahan supporting reformists. These estimates hold that reformists will dominate the new parliament, with the next legislative period due to commence on May 28.
The election results have been seen as an indication of Iranians' support for their reformist president, who limited the country's nuclear programme to obtain the lifting of international sanctions.
With Rowhani reformists in parliament, the way also is paved for his re-election in June next year.