The mayor of Iran's capital Tehran has resigned after hardliners criticized him for attending a ceremony in which primary school girls danced.

The Thursday report by Iranian media said Mohammad Ali Najafi submitted his resignation to Tehran's City Council.

Last week, prosecutors summoned Najafi for attending the ceremony in which a group of under-age girls danced in a ceremony held to commemorate International Women's Day.

Hardliners used the case to increase pressure on the U.S.-educated technocrat who came into office in August promising to fight corruption.

Official reports say the municipality had some $10 billion in debt, including $1 billion to contractors when Najafi took office.

Najafi succeeds Mohammd Bagher Qalibaf, a conservative politician who briefly stood as a candidate against President Hassan Rouhani in May before dropping out.