Iran’s Supreme Leader Ayatollah Mojtaba Khamenei said that avenging his slain predecessor and father was “the demand of the nation” and “must certainly” take place, according to a written message released on his Telegram account, Reuters reports.

“We pledge to avenge the blood of the martyred leader and all the martyrs of these two wars from the criminal and disgraced killers,” Khamenei said in the message.