Iranian authorities have mercilessly slaughtered more than 500 people in a ruthless crackdown on the nationwide anti-regime uprising — in what human rights groups have warned is a state-sponsored “massacre” in progress.

Disturbing images show body bags piling up in Tehran, prompting former top military officials to urge President Trump to take decisive action.

At least 496 protesters have been killed in the two weeks of unrest that has engulfed the oppressive theocracy, according to alarming estimates released Sunday from US-based Human Rights Activists in Iran (HRANA).

In addition, 48 security personnel have lost their lives and more than 10,600 people have been arrested, the rights group said.

Retired Army Gen. Jack Keane warned Sunday that many of those jailed would likely be executed. 

“Things here are very, very bad,” a source in Tehran told the BBC on Sunday. “A lot of our friends have been killed. They were firing live rounds. It’s like a war zone, the streets are full of blood. They’re taking away bodies in trucks.”

Mohammad Movahedi Azad, Iran’s attorney general, denounced anyone taking part in the civil unrest as an “enemy of God” — a crime that carries the death penalty in the Islamic dictatorship.

HRANA’s latest death count more than triples its previous casualty figures provided just hours earlier on Sunday, in which the NGO said 162 had died. The Post is unable to independently verify the figures.

The dramatic revision to the death toll comes as the New York-based Center for Human Rights in Iran (CHRI) said reports of mass killings have started emerging, despite the government shutting down access to the internet nationwide on Thursday night.

“Hospitals were overwhelmed, blood supplies are critically low, bodies are being piled up, and the number of casualties is rising by the hour,” CHRI warned, citing grisly witness accounts describing Iranian security forces shooting protesters in the eyes with rubber bullets and metal pellets.

“Disturbingly, many protesters have been shot in the eyes, and eyewitnesses have reported the use of snipers, military rifles, and surveillance drones,” the group added.

“CHRI warns that a massacre is unfolding,” it ominously warned. “The world must act now to prevent further loss of life.”

Speaking on Fox News’ “Live, Liberty & Levin” on Saturday, Keane said the Trump administration should give the regime one last chance to end the violent crackdown on protesters before unleashing US military might to “take down” Iranian leaders behind the killings.

“I think the president could give one more warning and then take down some of the leaders responsible for conducting violence against the Iranian population,” he said.

“I believe that we have the leverage here to actually curtail this behavior.”

In addition to those already killed, Keane highlighted the many thousands of protesters who have been jailed.

“And in jail, they will execute them,” he warned.

Retired Navy Vice Adm. Robert Harward said during a Sunday appearance on “Fox & Friends Weekend” that regime change in Iran is “inevitable.”

Meanwhile, Reza Pahlavi, the Crown Prince of Iran living in exile in the US, beseeched President Trump not to abandon the Iranian citizens whom his promise of support has inspired.

“Your words of solidarity have given Iranians the strength to fight for freedom. And while Khamenei and his thugs call for ‘Death to America,’ the Iranian people are renaming streets after you,” Pahlavi said in a statement on X.

“They know you have their back and will not abandon them like Obama and Biden. After the fall of this terrorist regime, they will be your best partner for peace and prosperity,” he continued.

“Help them liberate themselves and Make Iran Great Again!”

The protests initially erupted on Dec. 28 after economic concerns reached a fever pitch in Iran, where prices have spiked and the currency has plunged — but they have since morphed into the biggest anti-government demonstrations in years. 

Protesters took to the streets in massive numbers, turning their ire against the ruthless regime that has held power since the 1979 Islamic Revolution.

Trump has repeatedly vowed that the US would intervene militarily if the Iranian government responded to the demonstrations by committing acts of violence against its citizens.

“You better not start shooting because we’ll start shooting too,” Trump warned last week.

In response, Supreme Leader Ayatollah Ali Khamenei accused Trump of having hands “stained with the blood of Iranians” in defiant remarks aired Friday.

“[The terrorists] are ruining their own streets … in order to please the president of the United States because he said that he would come to their aid,” Khamenei told a crowd of supporters shouting “Death to America!”

Behrang Borhani, head of media relations at the Organization of Iranian American Communities (OIAC), urged Trump to keep up a pressure campaign — but stopped short of calling for military action.

“What Iranians are asking for is not boots on the ground, but accountability and sustained pressure,” he told The Post.

“Targeted sanctions against those responsible for the killings, international investigations, diplomatic isolation of the perpetrators, and concrete support for internet access and secure communications so the people can communicate in real time.”

An undeterred Tehran, meanwhile, threatened to respond to any US military strikes by targeting US military bases in the region.

The regime also doubled down on blaming America for the unrest on Sunday, declaring a three-day period of mourning to honor those killed in the protests — whom state-run TV network Islamic Republic of Iran Broadcasting (IRIB) referred to as “martyrs of the National Resistance Movement of Iranians against America and the Zionist regime.”

The Trump administration launched a targeted bombing campaign against Iran in June, dropping at least six “bunker buster” bombs across three sites, including the Fordow nuclear enrichment plant, a fortified facility hidden nearly 300 feet beneath a mountain.

Officials are now evaluating several possible responses to the rapidly rising civilian death toll, including a massive aerial strike campaign on numerous Iranian military targets — though Washington has yet to reach consensus on a plan of action.

The administration has the wind at its back following the successful capture of ex-Venezuelan dictator Nicolas Maduro, who was brought to the US last week along with his wife, Cilia Flores, to face narco-terrorism, weapons and other charges.

Additional reporting by Ryan King