The funeral procession carrying the coffin of Iran’s slain supreme leader Ali Khamenei began making its way through the streets of Tehran, AFP reports.

“We ask the public to go peacefully to Azadi Square,” where the procession is expected to pass, said General Hassan Hassanzadeh, a senior commander in Iran’s Revolutionary Guards.

Authorities fear deadly crowd crushes like those that occurred in 1989 during the funeral of Ayatollah Ruhollah Khomeini, Khamenei’s predecessor.