The funeral ceremonies for Ayatollah Ali Khamenei, Iran’s slain supreme leader, are underway, a weeklong event held across five cities and two countries, drawing foreign dignitaries and millions of Iranian mourners.

But it remains unclear if his son and successor, Ayatollah Mojtaba Khamenei, will attend. He has neither been seen in public nor his voice heard because of security concerns since being appointed in March.

“The issue of the supreme leader attending is not within my authority and information,” Ali Akbar Pourjamshidian, the head of the funeral planning committee for Mr. Khamenei, said at a news conference last week. “If there is any plan, his office will provide the details.”

Mr. Khamenei has been hiding in a bunker, and access to and communication with him has been limited. He was believed to have been injured in the same strikes that killed his father when Israel and the United States bombed the family’s compound on the first day of the war, Feb. 28.

He was absent at the memorial ceremony for his wife, Zahra Hadad-Adel, on Wednesday night in Tehran. Ms. Haded-Adel was also killed, along with the couple’s teenage son and other family members, in the strikes.

Many of Mr. Khamenei’s followers had hoped to finally get a glimpse of him at the funeral. But concerns about any Israeli attempts to assassinate Mr. Khamenei or track his movements to discover his hide-out made his security team reject the idea of his attendance, according to two members of Iran’s Islamic Revolutionary Guards Corps who are familiar with the planning and did not want to be identified by name because they were not authorized to speak publicly.

“His safety should definitely be the priority,” said Ehsan Hosseini, a supporter of Mr. Khamenei’s, who planned to attend the ceremony in Tehran on Saturday. “Whatever decision his office makes about his attendance will be the right one.”

Mohammad Hossein Khoshvaght, whose sister is married to the slain supreme leader’s other son, Mostafa Khamenei, told an Iranian news outlet, Ansaf News, in June that security experts had advised the new supreme leader “not to reveal himself in any way, even to the extent of releasing his voice.”

The two officials said the younger ayatollah, 56, told officials that he wanted to participate in at least some portions of the funeral ceremonies. He would like to attend the burial ceremony, scheduled for July 9 at a Shiite shrine of Imam Reza in the city of Mashhad, the officials said, and to recite the prayer of the dead over his father.

In his first public statement after taking power in March, Ayatollah Khamenei said that he had seen his father’s body and that sitting in his seat was a daunting endeavor.

Shirin Hakim contributed reporting.