TEHRAN, (Reuters) – Iranian security forces armed with batons and teargas clashed with supporters of the late dissident cleric Grand Ayatollah Hossein Ali Montazeri in two central cities on Wednesday, opposition websites said.

One report said plainclothes agents used teargas and pepper gas against people who were gathering for a Montazeri memorial service to be held in a mosque in the city of Isfahan, while another said women and children were among people beaten up.

Some opposition supporters were injured and dozens were arrested, according to reformist websites, whose reports could not be independently verified. There was no immediate comment from the authorities.

If confirmed, they would further highlight escalating tension in the major oil producer, six months after a disputed presidential election plunged the Islamic Republic into its deepest internal crisis since it was founded three decades ago.

Police chief Esmail Ahmadi-Moqadam warned the pro-reform opposition of “fierce” confrontation if it continued its “illegal” activities, the semi-official Fars news agency said.

Reformist former president Mohammad Khatami condemned the violence in Isfahan, Parlemannews reported.

“Imam Khomeini (Iran’s revolutionary leader) believed that the Islamic Republic was based on two pillars — freedom and independence. If these pillars become shaky … we will have tyranny again,” Khatami said.

“Calling anyone who raises his voice a traitor, despite him believing in the (Islamic) system, is a major deviation and should be corrected,” Khatami said.

The Jaras website said many demonstrators were hurt during the clashes in Isfahan, which occurred during the traditional third day of mourning for Montazeri, who died on Saturday night at the age of 87 in the holy Shi’ite Muslim city of Qom.

“Police fired teargas to disperse people … many people were injured … some arrested,” Jaras said.

Another reformist website, Parlemannews, said at least 50 opposition supporters, including four journalists, were arrested in Isfahan, one of Iran’s biggest and most historic cities.

The website said plainclothes agents used pepper gas on a cleric named Adib, who it said was an ally of opposition leader Mirhossein Mousavi and who was supposed to deliver the memorial service sermon, and arrested him by the Seyed mosque.

Security forces surrounded the mosque to stop people entering, the Rah-e Sabz website said.

“Montazeri mourners shouted slogans against the top authorities,” it said. “They are beating protesters, including women and children, with batons, chains and stones.”

The reported incidents took place two days after big crowds turned out in Qom for the funeral of Montazeri, when many people chanted anti-government slogans, websites said.

Montazeri, an architect of the 1979 Islamic revolution and a spiritual patron of the opposition, was a fierce critic of the hardline clerical establishment who denounced President Mahmoud Ahmadinejad’s re-election in June as fraudulent. His death occurred in the run-up to Ashura on Dec. 27, a politically important Shi’ite religious commemoration that offers the opposition another opportunity to show its strength.

Ahmadinejad’s re-election, in a vote the opposition says was rigged, kindled the biggest unrest in Iran’s 30-year history and split the political and clerical establishment.

The authorities deny poll rigging charges and have portrayed the huge opposition protests that erupted after the poll as a foreign-backed bid to topple the Islamic establishment.

Despite scores of arrests and security crackdowns, opposition protests have repeatedly flared up since the vote.

Referring to the city where Montazeri was born, Jaras said: “Sporadic clashes started from Tuesday night in Najafabad and

still continued. The situation is tense in the city. People are chanting anti-government slogans.”

In nearby Isfahan, it said plainclothes security agents surrounded the house of a leading pro-reform cleric, Ayatollah Jalaleddin Taheri, who had called on people to attend the memorial service for Montazeri.

“I tried six different ways to get to the mosque but they were all blocked,” Parlemannews quoted him as saying.

Police sealed off streets in the area where the clashes took place and motorists honked horns to protest against the security forces’ treatment of demonstrators, Jaras said.

The opposition reports from Isfahan and Najafabad could not be confirmed independently because foreign media are banned from reporting directly on protests.

Government supporters staged counter rallies in Qom on Tuesday and Wednesday, condemning “the insult against sanctities” during Montazeri’s funeral, official media reported. “This is the last time that something like that will happen in Qom. This is not a place for hypocrites,” Grand Ayatollah Hossein Nouri Hamedani told the crowd, state television said.

Iran’s internal unrest has complicated the dispute over the Iranian nuclear programme, which the West believes may have military ends, not just civilian purposes.

Montazeri played an important part in the 1979 revolution that overthrew the U.S.-backed shah and was once named to succeed Ayatollah Ruhollah Khomeini as supreme leader. But he fell from grace after criticising the mass execution

of prisoners in the late 1980s.