A hearse carrying coffins is passing through large crowds of mourners in Tehran, where a massive procession for Iranian Supreme Leader Ayatollah Ali Khamenei is underway.

Crowds of Iranians marched through the streets of Tehran on Monday in a funeral procession for slain ​leader Ayatollah Ali Khamenei, the biggest day yet in a week of massive memorial ceremonies demons...

NBC News’ Richard Engel reports from Tehran.