Iran's security forces are using lethal force against protesters nationwide, informed sources told Iran International, with preliminary estimates pointing to mass casualties as a sweeping crackdown unfolds amid a near-total internet shutdown.

An Iranian protester took down the Islamic Republic flag and replaced it with the pre-1979 Lion and Sun flag at Iran’s embassy in London during Saturday protests.

Tehran is signaling no retreat in the face of escalating protests, issuing fresh threats and hardening its rhetoric even as unrest continues across multiple cities.

Dozens of people have been killed in protests across Iran in recent days, according to human rights groups and witness accounts, with the full scale of casualties from Thursday night still unknown after authorities imposed a nationwide internet blackout.

In a speech on Friday, Supreme Leader Ali Khamenei left little doubt that Tehran intends to confront the current wave of protests with force rather than concession.

Iran’s Supreme Leader Ali Khamenei on Friday warned US President Donald Trump that he would be brought down, as he spoke about protests and accused foreign-backed forces of trying to destabilize Iran.

Iranian officials have begun publicly blaming one another and foreign foes for ongoing unrest across the country, exposing sharp divisions in Tehran on one of the greatest challenges yet to the Islamic Republic.

Chinese independent refiners are expected to increasingly rely on Iranian heavy crude in the coming months, as Venezuelan oil shipments to China stall after the United States moved to redirect Venezuelan exports, traders and analysts told Reuters.

Iran’s rial fell to a fresh record low on Tuesday on unofficial markets, with the US dollar quoted at about 1.47 million rials as authorities seek to defuse public anger over soaring prices.