Fresh protests erupted in several Iranian cities on Friday, with thousands of demonstrators protesting over high prices and shouting slogans against the government.

Around 300 people protested in Kermanshah, a city in western Iran, on Friday, according to Fars. Police reportedly intervened after protesters damaged public property.

Protests also broke out in the capital Tehran, according to social media.

The anti-government rallies, thought to be the biggest show of public defiance since 2009, began on Thursday in the Mashid, with authorities arresting 52 protesters over the unrest.

The semi-official ILNA news agency and social media also reported demonstrations in other cities in Razavi Khorasan Province, including Neyshabour and Kashmar, with footage showing a heavy police presence as people chanted "Death to [President Hassan] Rouhani".

Chants in the holy city of Qom tonight, the spiritual center of #Iran: “We don’t want an Islamic Republic!” pic.twitter.com/ilawigFGej

— Holly Dagres (@hdagres) December 29, 2017

Hassan Rouhani’s 2015 deal with world powers, to curb Iran’s nuclear program in return for lifting most international sanctions, has yet to bring the broad economic benefits the government has promised.

The prices of several staples, including eggs, have risen by up to 40 percent in recent days, according to the Associated Press news agency.

Eshaq Jahangiri, Iran's first vice president, acknowledged that "there is an increase in the prices of some products", but said "the government is working on fixing the causes of the high prices".

Jahangiri also cast doubt on whether the protests were solely motivated by economic issues.

"The people behind what is taking place think they will be able to harm the government, but when social movements and protests start in the street, those who have ignited them are not always able to control them," he said.

Meanwhile, the US State Department has expressed its support for the protests and condemned the arrest of peaceful demonstrators.

A statement on Friday said: "Iran's leaders have turned a wealthy country with a rich history and culture into an economically depleted rogue state whose chief exports are violence, bloodshed and chaos."

It added: "As President Trump has said, the longest-suffering victims of Iran's leaders are Iran's own people."

"We urge all nations to publicly support the Iranian people and their demands for basic rights and an end to corruption."