Of 826,649 valid votes cast at 1,631 polling stations across the country, Rohani received 401,949, with his closest competitor, Tehran Mayor Mohammad Baqer Qalibaf, getting 126,896 votes, Najjar said on state television.

In third place was Iran's chief nuclear negotiator, Saeed Jalili, with 119,294 votes, followed closely by Mohsen Rezaie, a former head of the elite Revolutionary Guard, with 109,089 votes.

Trailing the field were former Foreign Minister Ali Akbar Velayati with 55,990 votes, and little-known former minister Mohammad Gharazi with 13,431 votes.

Polling stations stayed open for up to five hours later than planned as millions of Iranians turned out to cast their votes. An announcement of initial results by the Interior Ministry, scheduled for around 1:30 a.m. local time, was then postponed by several hours.

Authorities had earlier estimated a turnout of over 70 percent. If accurate, the votes counted so far would represent less than 2.5 percent of total votes cast. (Reporting By Yeganeh Torbati and writing by Marcus George in Dubai; Editing by Peter Cooney)