QOM, Iran, Dec. 21 (UPI) -- Mourners with the opposition movement in Iran chanted anti-government slogans at the Monday funeral for dissident cleric Grand Ayatollah Hossein Ali Montazeri.
Montazeri, 87, died of cardiac arrest during the weekend. Once seen as a possible supreme leader, the cleric fell out of favor with the hard-line regime amid disputes over civil rights.
Supreme Leader Ali Khamenei issued a statement commemorating the dissident cleric, Iran's state-funded broadcaster Press TV reported.
"Montazeri spent a long period of his life serving the late founder of the Islamic Revolution (Ruhollah Khomeini) and made many efforts and suffered much hardship for advancing this cause," he said.
Montazeri emerged as a spiritual leader of the so-called Green Movement that grew up around the dissent that greeted the disputed June election victory for Iranian President Mahmoud Ahmadinejad.
The grand ayatollah as recently as last week blasted the clerical regime in Iran for exploiting election protesters who vandalized pictures of Khomeini, saying the conservative leadership was "defaming" the late cleric.
Opposition leaders and defeated presidential candidates Mir Hossein Mousavi and Mehdi Karroubi attended the Monday funeral for Montazeri in the holy city of Qom. Opposition Web sites, The Wall Street Journal reports, said there were minor skirmishes between mourners and the state militia.
Tensions are expected to escalate during the holy period of Muharram, which culminates with Ashura celebrations Dec. 28.