Mourners thronged a vast prayer complex in Tehran on Saturday as the week-long funeral ceremonies of Iranian Supreme Leader Ayatollah Ali Khamenei began with the national anthem, religious eulogies and readings from the Koran. 15 million people are expected to attend the former leader's funeral, according to Iranian authorities, FRANCE 24's Reza Sayah said, reporting from Tehran, adding that the event would take place also in neighbouring Iraq.