Thousands of mourners gathered at Tehran’s Grand Mosalla, one of Iran’s largest religious and cultural centers, to attend memorial ceremonies for Ayatollah Ali Khamenei, according to Iranian state media.

The reports said people from different parts of the country arrived in large numbers to pay their respects. Coffins said to belong to members of his family, including his daughter, daughter-in-law, son-in-law and granddaughter, were also placed before mourners during the ceremony.

Iranian media reported that Khamenei’s body was transferred to the Imam Khomeini Mosalla complex in southern Tehran, where emotional scenes were witnessed as mourners offered prayers and condolences.

Tributes have continued from leaders and officials of several countries. Delegations from Russia and China were also reported to have attended the memorial events and expressed their condolences.

According to the announced schedule, the funeral procession will travel through several cities in Iran and Iraq. Authorities expect more than 20 million people to participate in the funeral procession. The main funeral prayer is scheduled for the morning of July 5, while burial is planned in Mashhad on July 9.

Iran has declared July 6 a nationwide public holiday. Security has also been tightened, with around 150,000 police personnel deployed during the ceremonies. Iranian authorities said Tehran’s airspace will be closed on July 6, while Mashhad’s airspace will be shut on July 9.

Memorial gatherings are also planned in the Iraqi cities of Baghdad, Kadhimain, Karbala and Najaf. Pakistani Prime Minister, Field Marshal, Deputy Prime Minister Ishaq Dar, Interior Minister Mohsin Naqvi, Bilawal Bhutto Zardari, Murad Ali Shah and other officials were also reported to have attended a condolence gathering.