Iran on Tuesday rejected as "utter lies" unofficial casualty figures given for street violence that erupted last month during demonstrations against a shock decision to hike fuel prices.

Protests erupted in Iran on November 15 after the announcement that petrol prices were going up by as much as 200 percent with immediate effect.

Banks and petrol stations were torched and shops looted in the violence which was quickly quashed by authorities who also imposed a week-long near-total internet blackout.

"I explicitly announce that the numbers and figures that are being given by hostile groups are utter lies and the statistics have serious differences with what they announced," Iran's judiciary spokesman Gholamhossein Esmaili said.

"They announced some numbers as well as some names... Their claimed numbers are sheer lies and fabricated," he said, in remarks aired on state television.

"The names they have given are also lies," Esmaili said, adding that they included people who were still alive and others who passed away normally.

The authorities have not yet given any overall death toll for the unrest.

London-based human rights group Amnesty International said on Monday that at least 208 people were killed in the crackdown.

"The number of people believed to have been killed during demonstrations in Iran that broke out on 15 November has risen to at least 208, based on credible reports received by the organisation," it said.

Amnesty, whose previous death toll was 161, added that the actual number of people killed was likely to have been higher.

Esmaili accused foreign organisations and media of spreading "propaganda" and being behind the killings.

The judiciary spokesman said 300 people arrested over the unrest were still in custody in Tehran, without giving a country-wide figure.

Mourners attend the funeral of Revolutionary Guards commander Morteza Ebrahimi, one of the deaths during last month's unrest that the Iranian authorities have confirmed
Mourners attend the funeral of Revolutionary Guards commander Morteza Ebrahimi, one of the deaths during last month's unrest that the Iranian authorities have confirmed AFP / ATTA KENARE

Many had already been released after they were found to have been innocent, he added.

"We as the judiciary branch in no way consider as thugs or rioters those who took to the streets to merely voice their objections, even though they didn't have a legal permit for their street gatherings," he said.

His remarks came after state television said on Monday night that Iranian security forces had no choice but to resort to "tough confrontation" when the violence broke out.

It also rejected reports in foreign media that had been "hyping up" the number of people killed.

"The security forces had no choice but to resort to authoritative and tough confrontation in order to save people from the hands of the rioters, and a number of rioters were killed," the report said.

The broadcaster said "thugs and rioters" had attacked sensitive sites, including military bases, with firearms and machetes and "in some areas had taken people hostage".

It said the incidents occurred in the cities of Bandar Mahshahr, Fardis, Malard, Sadra, Sirjan, Shahriar and Shahr-e Qods.

The report categorised those who died in the unrest as "thugs and rioters", the security forces, passers-by and peaceful protesters.

The governments of the United States, France and Germany have condemned Iran over the bloodshed.

The unrest started hours after it was announced that the price of petrol would rise from 10,000 rials per litre to 15,000 (12 US cents) for the first 60 litres, and to 30,000 rials for any extra fuel bought after that each month.

Iran's economy has been battered since last year, when President Donald Trump unilaterally withdrew the United States from a 2015 nuclear agreement and reimposed crippling sanctions.

The government said proceeds from the fuel price hike would go to the most needy people in the country.

State news agency IRNA said the payments had since been made in three instalments between November 18 and 23.