TEHRAN- Tens of thousands of government supporters rallied in cities across Iran on Wednesday swearing allegiance to the clerical establishment and accusing opposition leaders of causing unrest in the Islamic state.

Iran's police chief on Wednesday warned supporters of opposition leader Mirhossein Mousavi only to expect harsh treatment if they joined illegal anti-government rallies, three days after eight protesters were killed in demonstrations.

Tens of thousands took part in the government-organised demonstrations, which state television broadcast live, chanting slogans against the opposition leaders Mousavi and moderate defeated presidential candidate Mehdi Karoubi.

You should repent ... otherwise the system will confront you as a 'mohareb' (enemy of God), cleric Ahmad Alamolhoda told reformist leaders at a Tehran rally, state TV reported. Under Iran's Islamic sharia law the sentence for a mohareb is death.

In Tehran, crowds burnt American and British flags.

There was no word about any opposition supporters on the streets on Wednesday, despite talk of demonstrations on reformist websites. Foreign media are restricted from moving around to report on such protests which are illegal.

In Iran's bloodiest unrest since the aftermath of the disputed June 12 presidential election, eight people were killed on Sunday and at least 20 pro-reform figures, including three senior advisers to Mousavi were arrested.

Raising the stakes further in the crisis, a representative of Iran's Supreme Leader Ayatollah Ali Khamenei said on Tuesday that opposition leaders were enemies of God.

Television footage of the rallies in various cities showed people chanting Mousavi is responsible for bloodshed ... We support our Supreme Leader. Some of them carried pictures of Khamenei. Similar rallies took place on Tuesday.

Since the deadly weekend clashes during the Shi'ite Muslim religious ritual of Ashura, political turmoil has entered a new phase in Iran with the clerical establishment piling pressure on the reform movement to end street protests.

People want the leaders of sedition to be punished. We will not remain silent over insulting the religion, one speaker told a Tehran rally, state TV reported.

Oil prices briefly rose above $79 a barrel to a fresh five-week high on Tuesday, supported by expectations of colder U.S. weather and concerns over political unrest in Iran.

Iran's police chief said on Wednesday there was no more room for tolerance over participants in illegal rallies.

Those who participate in illegal rallies will be confronted more harshly and the judiciary will confront them more decisively, said Esmail Ahmadi-Moqadam, the official IRNA news agency reported. Some of Sunday's protesters are ... considered as mohareb and will be confronted firmly.

President Mahmoud Ahmadinejad, locked in a row with the West over Iran's nuclear programme, said that the opposition rallies on the religious ritual of Ashura was a foreign-backed nauseating masquerade.

Pro-government demonstrators also chanted Death to America and Death to Britain, state TV reported. Iran has accused foreign powers of meddling in its affairs, which has provoked robust denials.

When the June poll returned hardline Ahmadinejad to power, his reformist opponents cried foul and thousands of Iranians took to the streets in the biggest anti-government unrest in the 30-year history of the Islamic Republic.
Authorities deny vote-rigging but the protests were showing no sign of subsiding six months after the election and despite a determined crackdown on protesters and opposition leaders.

The elite Revolutionary Guards on Tuesday accused the foreign media of conspiring with the opposition to harm Iran.

Hardliners who took to the streets on Tuesday also called for the punishment of opposition leaders. The opposition website Jaras said students at two Tehran universities clashed with hardline Basij militia.

We have asked the judiciary to arrest the leaders of this sedition, said hardline MP Hasan Norouzi, without saying just how many lawmakers made the demand. Karoubi, Mousavi and all those who ignite tension should be arrested and tried.

Analysts say the arrest of senior opposition leaders would increase tensions in the country. The opposition says more than 900 protesters were arrested on Sunday but police said 500 rioters were arrested, with 300 still in detention.

Police said the suspicious deaths on Sunday were under investigation, denying opposition claims that the people were killed by police.

Iran's Supreme National Security Council confirmed eight deaths, but Tehran's prosecutor dropped the number to seven.

The semi-official Fars news agency said Mousavi's nephew, who was killed in the bloodshed, was buried on Wednesday at Tehran's Behesht-e Zahra cemetery.

(Additional reporting by Reza Derakhshi)