0154 GMT October 16, 2019
The Tehran conference opened in a ceremony attended by President Hassan Rouhani, IRNA reported.
Several foreign ambassadors to Tehran, a number of Iranian lawmakers as well as the Friday-prayer leaders are present in the event.
Beirut hosted a conference on World Mosque Day to condemn Israel's atrocities and its desecration of al-Aqsa Mosque.
The conference was organized by al-Quds International Institute.
The event also expressed solidarity with the Palestinians living in the holy city of Beit-ul-Moqaddas.
August 21 marks the anniversary of the 1969 al-Aqsa Mosque fire, the origins of which are still being disputed over 40 years after the incident occurred. The day is called World Mosque Day in remembrance of the event.