50 candidates are competing to win the remaining 25 seats left for Tehran in the runoff elections being held May 4 in the capital and a number of other cities throughout the country, Fars News Agency reports.

The polling stations opened at 8 am (0330 GMT) in the morning and are due to close at 6:00 pm (1330 GMT). But the deadline would be extended if there is heavy turnout.

According to Iranian interior ministry data, about 135 candidates are vying for the remaining 65 parliamentary seats.

Over 14,323 polling stations have been set up for people to elect representatives to the parliament.

A total of 225 candidates succeeded in securing the required majority of votes to win parliamentary seats in the first round.

The run-off vote for the remaining 65 parliament seats is being held in the Iranian capital of Tehran and 17 other provinces.