Article published on the 2009-12-20 Latest update 2009-12-20 16:37 TU
Opposition supporters have called for a gathering to mourn Montazeri at Tehran's Mohseni square on Sunday, according to the opposition website Rahesabz, which said that there have already been "sporadic gatherings" in the capital.
Meanwhile, internet connection slowed to a crawl, as has been the case whenever the authorities anticipate opposition demonstrations.
Montazeri is to be buried in the shrine of Masoumeh, a revered Shia-Moslem figure, in Qom on Monday.
"Thousands of residents of Isfahan, Najafabad and other cities are going to Qom to attend the funeral on Monday," says the Parlemannews site.
Foreign media have been banned from covering the ceremony.
"He acted as the clerical figure of rioters in the post-election incidents and his unfounded statements were widely welcomed by anti-revolutionary media," Irna said, referring to Montazeri's criticism of repression of demonstrations after this year's presidential election.
State television reported that he died of "illness and senility".
Montazeri was once designated the successor to Ayatollah Ruhaollah Khomeini, but resigned a few months before the Islamic revolutionary leader's death after criticising political and cultural restrictions.
He later questioned the theological credentials of current supreme leader Ayatollah Ali Khamenei and was placed under house arrest in 1997. He was freed five years later on health grounds.
He regularly met pro-reform activists and criticised President Mahmoud Ahmadinejad's policies, calling for direct talks with Washington over Iran's uranium enrichment programme.