Authorities vowed to arrest leaders of the protests that started last Friday, in which police stations were attacked, petrol pumps torched and shops looted, and which Iran has blamed on a plot by foreign enemies.

While the Internet remained mostly blocked for a fifth day, state TV showed footage of what it said were spontaneous pro-government rallies to celebrate that the conspiracy had been defeated.

Crowds chanted messages such as "death to seditionists, death to America" and "the blood in our veins is a gift to our leader" in cities including Qom, Isfahan, Shiraz, Bandar Abbas and Kerman.

In the days of unrest, "incidents, big and small, caused by the rise in petrol price took place in (a little) less than 100 cities across Iran," said a statement on the Guards' official website Sepahnews.com.

It said the "incidents were ended in less than 24 hours and in some cities in 72 hours" as a result of the "armed forces' insight and timely action".

Protest leaders were arrested by the Guards' intelligence arm in the province of Tehran and Alborz as well as in the southern city of Shiraz, said the statement.

The "arrest of the rioters' leaders has contributed significantly to calming the situation," it added.

- 'People's vigilance' -

A top Iranian security official, Rear Admiral Ali Shamkhani, vowed that "every single one of the rioters, wherever in Iran they may be, will be identified and punished".

"Enemies wanted to exploit the Iranian nation's protest regarding livelihood issues but failed due to the people's vigilance," Shamkhani, secretary of the Supreme National Security Council, was quoted as saying by Mehr news agency.

Iran's neighbour Iraq has also recently been struck by anti-government protests, with demonstrators voicing resentment against what they describe as Tehran's meddling in their country.

The full extent of the bloodshed in Iran remained difficult to ascertain given the near-total internet restriction.

Officials have confirmed five deaths, of four security personnel and one civilian.

The United Nations human rights office has said it was alarmed by reports live ammunition had caused a "significant number of deaths".

London-based rights group Amnesty International said more than 100 demonstrators were believed to have been killed and that the real toll could be as high as 200.

- 'Armed rioters' -

Iran's mission to the UN disputed the Amnesty toll in a tweet, saying figures "not confirmed by the government are speculative" and in many cases a "disinformation campaign waged against Iran".

Iran's ambassador to Britain Hamid Baeidinejad called those who had attacked public property "organised armed rioters" in a tweet.

He also said they had planned to "detonate Asaluyeh refinery" in southern Iran and to "sabotage the national phone system."

The internet blackout remained largely in effect on Thursday, with Iranians abroad tweeting hashtags like #Internet4Iran and calling for an end to the outage.

It was the powerful national security council that made the decision to pull the plug on internet access, according to semi-official news agency ISNA.

Iran's telecommunications minister said Wednesday the outage had caused some local businesses a "90 percent drop in transactions" and forced some Iranian companies dealing with foreign partners to temporarily shut down.

Reformist MP Ali Motahari argued that "continuing the internet blackout is not necessary, since calm has returned to the country," adding that the parliament would "react" if the outage continues.

ISNA said internet access and connectivity to apps such as "WhatsApp and Instagram" had been restored in the southern province of Hormzgan, but this could not be immediately verified.