The deaths in Qasem Soleimani's hometown of Kerman led to the ceremony being delayed.
The burial is the last in a series of funeral events that have brought millions on to the streets in Iran.
Soleimani's killing has raised fears of a conflict between the US and Iran.
The head of the Quds force was tasked with defending and projecting Iranian interests abroad, and was hailed as a hero by many in his home country. Immediately after his death, Iran threatened retaliation.