Iranians vote on Friday to elect a new president from six candidates, including a lone reformist who hopes he can challenge the dominance of conservatives in the Islamic republic.
A presidential election had not been due until 2025, but was brought forward after ultraconservative Ebrahim Raisi died in a helicopter crash last month.
The snap poll comes at a challenging time as Iran grapples with the economic impact of international sanctions amid heightened regional tensions over the Gaza war between Israel and Tehran's ally Hamas.
In April Iran fired more than 300 missiles and drones at Israel after an air strike in Damascus blamed on Israel killed seven Revolutionary Guards.
Israel carried out a reported retaliatory strike near Isfahan.
Polling is also being held just five months before a presidential election in the United States, Iran's sworn enemy and Israel's staunch ally.
Leading contenders for Iran's second highest-ranking office are conservative parliament speaker Mohammad Bagher Ghalibaf, ultraconservative former nuclear negotiator Saeed Jalili, and the sole reformist, Massoud Pezeshkian.
The others are conservative Tehran mayor Alireza Zakani, cleric Mostafa Pourmohammadi, and incumbent vice president Amirhossein Ghazizadeh-Hashemi, the ultraconservative head of the Martyrs' Foundation.
The six have staged largely low-key campaigns, which included televised debates where they vowed to tackle economic challenges and offered varied views on Iran's relations with the West.
Ali Vaez of the International Crisis Group says the new president will also have to tackle the challenge of the deepening "fissure between the state and society".
"Nobody has presented a concrete plan of how they are going to deal with a lot of these issues," he said.
- 'No way I'm voting' -
Supreme leader Ayatollah Ali Khamenei, who wields the ultimate authority in Iran, urged "high participation" on Friday.
In the 2021 election that brought Raisi to power, voters shunned the polls after many reformists and moderates were disqualified.
The turnout then was just under 49 percent -- the lowest in any presidential election in Iran.
People appear divided over whether voting will mean any key concerns being addressed.
These include the mounting effects of soaring inflation and the decline of the rial against the dollar.
"There's no way I'm voting," said Neda, an engineer who gave only her first name, in northern Tehran.
"No matter who takes the post, none of them is sympathetic with the nation. My vote won't affect anything," she told AFP.
In contrast, 60-year-old housewife Jaleh said she was rooting for reformist Pezeshkian, who comes "from the people" and could address unemployment and poverty.
Reformist figures including former president Mohammad Khatami and ex-foreign minister Mohammad Javad Zarif have endorsed Pezeshkian.
However, some Iranians view the 69-year-old reformist as lacking government experience -- he only served as health minister about 20 years ago.
Of the main contenders, Ghalibaf is a veteran politician and former member of the Islamic Revolutionary Guard Corps, ideological defenders of the republic after the 1979 revolution.
