BAGHDAD: Thousands of Iraqis on Friday mourned Abdul Aziz Al-Hakim, a leading Shiite figure whose death could heighten political instability before national election many fear may be marred by violence.

Al-Hakim, who headed one of Iraq’s most powerful parties, the Supreme Islamic Iraqi Council (ISCI), died in Tehran on Wednesday where he was being treated for lung cancer.

A sea of people, some waving black banners, walked alongside Al-Hakim’s hearse toward a mosque in Baghdad, one of several sites where his casket is expected to be taken before being buried in Najaf on Saturday.

Iraqi leaders and other officials gathered at the Baghdad airport earlier on Friday to receive his body from Iran. Some sobbed audibly and flowers were thrown on Al-Hakim’s coffin as it was carried off the plane. Senior Iraqi officials sat in a mourning tent nearby specially constructed for the ceremony.

Iraq’s Prime Minister Nuri Al-Maliki, President Jalal Talabani and other senior figures offered their condolences to Ammar Al-Hakim, one of Hakim’s sons and a likely successor as the head of ISCI.

A member of Al-Maliki’s governing coalition, ISCI on Monday said it would lead a new, mostly Shiite alliance to compete in January’s election with the notable absence of Al-Maliki, raising questions about a split among Iraq’s majority community.