Dozens of Syrian refugees cluster night and day around the wooden picnic tables of a park on the outskirts of Urfa in Southern Turkey. Most of them come from the Syrian city of Raqqa and arrived only recently.

They're part of the accelerating exodus that's already driven 2 million civilians out of the war-torn country. One year ago, that number stood at below 250,000 according to the UN Refugee Agency.

Persistent air strikes by the regime and widespread shortages were bad enough, the refugees said. The takeover of their city by an al Qaeda group over the summer was the last straw.

"All Islamic now in Raqqa. All Islamic," says Mohamed, a 23-year-old football player who traveled to Turkey with his family just three days earlier.

Located about 190 kilometers east of Aleppo, Raqqa became the only provincial capital fully controlled by the armed opposition in Syria in March. Six months later, a single radical group - Dawlat al-Islamiyya, the al-Qaeda brigade also known as the Islamic State of Iraq and Syria (ISIS) - is ruling the town.

Sharia state

Its stated goal is to carve out a Sharia-ruled caliphate in opposition-held areas. Mohamed said they've already started to impose a strict version of Islamic laws: Even a stroll in a park can get you in trouble these days.

"One day during Ramadan, I saw a couple walking in the park. Then I see the Islamics coming to them. 'Why are you walking with a girl?,' they asked the man. 'She's my sister,' the man replied. 'Give me your (ID) card... No you're a liar. See the card? She's not your sister.' And then they took the man."

Mohamed (left) has managed to escape from the clutches of radical militants in Syria

Mohamed said he doesn't know what happened to him next. He punctuates the story with a laugh, but he knows this isn't a joke. His uncle escaped Syria two months ago. For him, leaving Raqqa was a matter of life and death.

Abu Mossaab worked as a civil engineer for Raqqa governorate. He was kidnapped shortly after radical Islamist groups gained a foothold in the city late in the Spring. Abu Mossaab says his captors didn't accuse him of anything. Money is all they wanted.

"I told them, just give me one reason for arresting me. If I stole something, if I killed someone, if I spied, just give me one witness. They said it's not your business. We just need money from you if you want to get out of here."

It took a month and a half for his family to collect ransom payment: 5 million Syrian pounds, about 30,000 euros.

A few weeks after his release, Abu Mossaab was kidnapped again. But this time he managed to escape, and fled the country right away. He said his brother was killed on a street in Raqqa that very same day.

Lessons from Iraq

Following a playbook well-tested in Iraq, al Qaeda has ramped up its scare tactics in Raqqa. Kidnappings and intimidation are widespread - to the point that many refugees in Turkey don't feel comfortable disclosing their full name.

Abu Mossaab's wife hovered around anxiously during the interview, begging her husband to stop.

Mohamed and his family are staying in an empty house on the outskirts of town

"She's afraid," said Mohamed, the young football player who's also their nephew. This fear of speaking up has an air of deja-vu, he quipped. "Before the revolution, you couldn't talk about Bashar. And now it's the same. People don't talk about the Islamists. It's not freedom."

The situation further deteriorated last month when a car bomb rocked the train station that served as headquarter for the local Free Syrian Army. The attack killed two FSA commanders, and drove the last-remaining local brigade out of the city.

Abu Milla, another refugee at the park in Urfa, said he was home, just 150 meters away when the car detonated. Radical Islamists had made little secret about their intentions, he said: There had even been an announcement days earlier by the mosque nearby that the FSA base would come under attack.

"The ISIS is worse than the regime," Abu Milla said. "To them, everyone is a takfiri" (The derogatory term used when a Muslim accuses another Muslim of apostasy).

American support

As for other refugees from Raqqa, Abu Milla said most of them are not Syrians. "They're Afghans, Chechens, Saudis, Kuwaitis... So of course I'm angry. But I can't just go to them and ask what they're doing in my country! They have Kalashnikovs. Some even wear TNT belts around their chests."

Raqqa is hardly the only place in northern Syria where the ISIS and FSA brigades have recently clashed. The assassination in July of top FSA commander Kamal Hamami at an ISIS checkpoint in Latakia province was the first salvo. Skirmishes have since broken out in the provinces of Idlib, Deir Ezzor, and Aleppo where internecine fighting reached a new level of violence this week with the ISIS storming the strategic border town of Azaz and expelling FSA brigades. In the latest developments, the two sides have now agreed on a ceasefire and an exchange of prisoners.

Some refugees in Urfa said they support a Western intervention because air strikes might help the Free Syrian Army and undercut Islamist groups. Others like Abu Mossaab, the twice-kidnapped engineer, went further. He said Americans should also consider strikes against Islamist groups.

"They should make it even," Abu Mossaab said when the perspective of a US-led air campaign was looming large two weeks ago. "Bomb the regime, and bomb the Islamist groups."

Trying to dislodge the ISIS though would be risky, he added. Chances of civilian casualties are high, and confronting them might only make them stronger. But the alternative is worse, with al Qaeda gaining more ground as the civil war drags on.

Abu Mossaab says he won't go back to Raqqa as long as they're ruling his hometown.