For Syrians still stuck in the once-thriving city of Raqqa, life under the thumb of the black-clad Islamic State thugs who patrol the caliphate’s unofficial capital has become a bleak tableau of misery and deprivation.

The 2,300-year-old city on the bank of the Euphrates has been ruled by Greeks, Romans, Bedouins and Ottomans, but the Islamist marauders who currently hold power have plunged it into an era of medieval darkness, where children are forced to donate blood and death sentences are meted out in the mosques where the city’s 220,000 residents once worshipped freely, say stranded residents. A daring network of activists still trapped in the city are risking their lives to get their desperate message out to the world in the hope that their city might one day be reclaimed from the grip of merciless jihadists.

"They’re calling for our blood to be spilled in the streets just because we highlight their injustice and criminality."

- Abu Ibrahim RaqqAwi, Raqqa is being Slaughtered Silently

“ISIS tries to scare us with constant death threats, but we are no longer afraid, we have become accustomed to death,” Abu Ibrahim RaqqAwi, the pseudonym of a lifelong Raqqa resident who in April, 2014, founded the activist campaign “Raqqa is Being Slaughtered Silently,” told FoxNews.com by email. “Prices are high, there is little water or electricity. There are no schools or universities. There is nothing important for us to do.”

With international journalists unable to cover events in Raqqa, RaqqAwi's group has sought to expose the horrors imposed by ISIS and counter claims that citizens welcome their new de facto government. The group has published first hand accounts, videos and photos from inside Raqqa through its Facebook page and social media, at great peril to members. The campaign has also included tagging city walls with anti-ISIS graffiti and distributing leaflets, but much of the effort has been stamped out by the terrorist army and several members of the group have fled the city, he said.

One Raqqa is being Slaughtered Silently who fled to Greece through Turkey told FoxNews.com he witnessed children being recruited as ISIS soldiers, with the approval of their desperate parents, who were promised money. He said the terror group instead sent the kids on suicide bombing missions, after telling them they would go to paradise. 

Drinking and smoking – including the Middle Eastern tradition of hookah – are banned in Raqqa, according to RaqqAwi. Prices for basic goods continue to skyrocket as the local economy teeters on the brink of total collapse. Streets are buried in garbage and sewage, and most public institutions are no longer functioning. Islamic State enforcers patrol the streets hounding citizens and hunting RaqqAwi and his cohorts. Anyone seen with a camera – and the ability to convey life inside Raqqa to the outside world – faces amputation of limbs or even execution on the spot at the hands of ISIS, or Daesh, as it is referred to in Syria and Iraq, he said.

“ISIS has issued death sentences in our names at the mosques, accused us of blasphemy and have said that we are apostates from our religion and that we must therefore be killed,” he said. “They’re calling for our blood to be spilled in the streets just because we highlight their injustice and criminality. Anyone who fights the Daesh or is heard talking bad about them will immediately be killed.”

Always predominantly Muslim, Raqqa is now being forced to live under the terrorist organization’s twisted and unforgiving interpretation of Shariah law. The only non-religious education permitted is in the form of Islamic State’s desperate appeal for doctors to tend to its wounded fighters, RaqqAwi told FoxNews.com. Men and women between 18 and 30 are forced to study medicine, and must draw blood from residents -- including children. The medical students must also treat Islamic State fighters wounded in battles with soldiers from the regime of President Bashar Assad, the Free Syrian Army rebels they once fought alongside, or by U.S.-led airstrikes, which continue to pound the region, but have not stemmed the deterioration of conditions in Raqqa.

“The hell known as ISIS is what you read about in newspapers, while we live it every day,” RaqqAwi said. “Freedom squares where we once stood and chanted against injustice and crimes committed by the Assad regime have turned into squares of execution where bodies of my countrymen hang on its wall.”

Life elsewhere in the sprawling, so-called “caliphate” of Islamic State leader Abu Bakr al-Baghdadi is no better, say those still trapped under ISIS rule. In the Iraqi city of Mosul, water and power is available for only a small portion of the day and a small tank of propane for cooking can cost as much as $150.

“Otherwise people are using wood to cook, like a thousand years go,” one Mosul native, identified as Baidaa, told FoxNews.com. “People only leave their houses when it is really necessary, they don’t even visit each other anymore. People sit around and wait for something… but they don’t know what.”

One Iraqi man who spent several years serving as an interpreter for U.S. Navy SEAL teams during Operation Iraqi Freedom said he is in sporadic contact with family members he left behind. The man, who fled to the U.S. in 2009, said his family paints a desperate picture of life in the northern Iraqi city whose population once stood at nearly 2 million, but is now a small fraction of that. The man, who goes by “Johnny Walker” to protect his family still in Iraq, said Mosul’s economy is nonexistent, and locals, including children, are being trained to carry weapons to protect the city from attack by U.S., Iraqi or Kurdish forces.

“Most people in Mosul don’t believe in Shariah Law, but now they have no choice,” Walker said. “One young boy – maybe 16 or 17 – was seen walking down the street in American-made, Western-style jeans, so ISIS broke his legs. They cut the electricity too, maybe to live like the time of the Prophet. But if that’s what they want, they should be fighting by the sword, too.”

One refugee from Mosul, who fled with her young family to a temporary camp in Iraq’s Kurdish region several months ago, said she had to leave after her 2-year-old daughter got cancer and they could no longer access adequate medical supplies.

“At least here the doctor comes twice a week,” she told FoxNews.com at the camp, where hundreds of tents stood against a punishing rain.

Syrians and Iraqis who have made it out of ISIS-controlled territory to refugee camps such as the Domiz camp in Duhok, Iraq, where some 1,800 families are hunkered down, only the U.S. offers hope for the future. They say they feel safe from ISIS in the camps.

“We know American soldiers will protect us,” one woman said defiantly. “Then it will be game over.”

But in Raqqa, Mosul and the countless smaller cities and villages where longtime residents remain trapped, living under the bloody sword of ISIS, fear persists that the daily scenes of beheaded bodies and devastated buildings is scarring children and damning the future.

“The hopes of entire generations have been destroyed,” RaqqAwi said.  “But we will continue our revolution and fulfill our dream, or we will die trying. We dream for Syria a free country – long live Syria – prosperous and strong.”