The US Treasury slapped punitive sanctions on Iran's communications minister, Mohammad Javad Azari Jahromi, Friday after the Tehran regime blocked internet communications amid violent protests triggered by a petrol price hike.

"We are sanctioning Iran's Minister of Information and Communications Technology for restricting internet access, including to popular messaging applications that help tens of millions of Iranians stay connected to each other and the outside world," said Treasury Secretary Steven Mnuchin in a statement.

"Iran's leaders know that a free and open internet exposes their illegitimacy, so they seek to censor internet access to quell anti-regime protests," Mnuchin said.

The protests erupted across the country on November 15, after the price of petrol was raised by as much as 200 percent.

Officials have confirmed five deaths, while Amnesty International said that more than 100 demonstrators were believed to have been killed after authorities reportedly used live ammunition to quell the protests, which brought attacks on police stations and petrol stations and some looting of shops.

The Treasury said Azari Jahomi is a former official of the Ministry of Intelligence who has advanced internet censorship since becoming minister two years ago.