Fears for the safety of dozens of Western captives—among them journalists and aid workers—kidnapped in northern Syria by al Qaeda factions are mounting amid signs they are being moved deeper into territory firmly under jihadist sway. Private security experts and Western intelligence sources say the captives are in the process of being transported closer to the Iraqi border in an operation directed by a Chechen commander.

The movement of the captives appears to be a precaution against them being freed as a consequence of furious rebel infighting that has plunged insurgent-held areas in northern Syria into chaos in the past two weeks.

Speaking on the condition they would not be identified, private security experts working on several abduction cases say a commander called Abu Omar al Chechen, a former Georgian soldier who has sworn allegiance to the emir of the Islamic State of Iraq and Sham (ISIS), Abu Bakr al-Baghdadi, is overseeing the movement of the captives amid heavy security.

“The Westerners are being moved in groups and individually in armored vehicles,” one of the security advisers told the Daily Beast. Foreign fighters, including Saudis, are guarding them, he says.

About 30 Western journalists—among them American freelancers James Foley and Austin Tice—have been abducted in Syria since the start of the country’s civil war. Most are thought to be in the hands of jihadists and other Islamist militants, although the State Department says it suspects the Syrian government is holding Tice. And one of the media outlets Foley worked for, Global Post, said in a statement last year they too suspected the Syrian government might now be holding him. Foley has been missing for more than a year.

Foreign aid workers have also been kidnapped, among them seven employees of the International Committee of the Red Cross, who were kidnapped in October in northwestern Idlib province. The Syrian Observatory for Human Rights, a London-headquartered pro-opposition group with a network of activists in Syria, accused al-Qaeda-linked ISIS for the abduction of the Red Cross workers.

And on January 3 five employees of the NGO Doctors Without Borders (MSF) were abducted from a shared house the organization was using in northern Syria. Those who disappeared were from Belgium, Denmark, Peru, Sweden and Switzerland, according to MSF. ISIS admitted responsibility for the abductions, saying it had “arrested European doctors who were spying on jihadist combatants.”

Like most agencies and media outlets that have had their workers seized, MSF has been cautious about sharing details, fearing publicity could further endanger their employees or wreck chances of any behind-the-scenes negotiations for the release of their workers.

The sources that spoke to The Daily Beast on the condition of anonymity gave the clearance for some information they have gathered to be published but asked for the names of the captives they are trying to track not to be disclosed. They said they had harbored hopes that some Westerners would be freed in the spiraling struggle for mastery underway in northern Syria between ISIS and a loose alliance of Syrian insurgents that has seen an estimated one thousand rebel fighters and civilians killed. But an ISIS pushback in recent days has dashed hopes of that happening.

Dozens of Syrian captives held by ISIS in their headquarters at a former children’s hospital in the city of Aleppo were freed when the al Qaeda group was pushed out of the city briefly. Two Swedish journalists and a Turkish reporter have also been freed recently.

“The shifting of the Western captives further east is a bad sign,” says a Western intelligence source. “It makes it less likely that either inadvertently or because of the actions of a more moderate rebel brigade they will be freed. It also indicates the jihadists have no intention of releasing the Westerners.”

According to the private security experts, ISIS has recovered from its surprise at the offensive mounted against it by other insurgents and become more organized in its handling of Western captives. “From our sources we have heard they want to move all foreign prisoners closer to the border with Iraq. Most of them are still being held in Deir ez-Zor province.” In recent weeks, ISIS has increased its grip on Iraq’s Anbar Province and the city of Fallujah, which abuts northeastern Syria.

Syrian Bedouin allies, some from clans affiliated to the Ougaidat tribe, are assisting al Qaeda factions in northeastern Syria and are helping the “managing of the transportation of foreign captives by providing security and logistics,” says a private security expert. “ISIS made a deal with them giving access to oil wells it controls.”

Ougaidat clans have been especially active in Deir ez-Zor and in towns and villages close to the Iraqi border such al-Mayadin and al-Bakamal. ISIS has long had a presence in Deir ez-Zor and the province served as a haven for al Qaeda operations against U.S. military forces in Iraq, according to Bill Roggio, managing editor of the Long War Journal, a publication of the Foundation for the Defense of Democracies, a Washington D.C.-based think tank. Before the civil war “with the help of the Syrian government, al Qaeda in Iraq used the region as a rear area to support attacks against U.S. and Iraqi forces.”

Many tribal leaders in Deir ez-Zor have sworn allegiance to ISIS and the smaller al-Qaeda affiliate Jabhat al-Nusra—and despite the two al Qaeda factions being at loggerheads elsewhere in northern Syria, the two have maintained cordial relations in the province.

The tribal assistance is crucial in the movement of the Western captives, who are being transported in armored vehicles amid tight security, according to private security experts. The fact that ISIS considers them more valuable is demonstrated by the fact that non-Western captives are being transported in ordinary cars, say the security sources and a former jihadist.

The commander entrusted to oversee the movement of the foreign prisoners is Abu Omar al Chechen, a red-haired jihadist whose real name is Tarkhan Batirashvili, according to private security experts from several Western security companies. Born in 1986 in the Pankisi Valley in northeast Georgia, both his parents are ethnic Chechens. According to the Wall Street Journal, as a young man, he joined Chechen militants on missions against Russian-backed troops and served later in the Georgian armed forces fighting in the 2008 Georgian-Russian war in an intelligence unit before contracting tuberculosis and being released from service.

He appears to have become radicalized after being jailed for 16 months in Georgia for illegal possession of weapons, telling a jihadi website that prison had transformed him. “I promised God that if I come out of prison alive, I’ll go fight jihad for the sake of God,” he said. In March 2012 he was the commander of the al-Nusra-linked group the Muhajireen Brigade, which was at the forefront of the overrunning of several major Syrian military bases including the rebel seizing of the Menagh Air Base north of Aleppo last year. He switched allegiance from al-Nusra to al-Baghdadi last November, joining the inner circle of ISIS commanders who are mainly Iraqis. On January 20, Russian-speaking ISIS fighters commanded by al-Chechen posted a video online supposedly showing a massive arms haul that they had seized from other rebel forces. The arms included 122 mm Grad rockets and tank shells.

A U.K. private security adviser said his firm had picked up that al-Chechen was increasingly working in Deir ez-Zor. “We were puzzled [as to] why at first,” he said. “Most of the abductions, we suspect, have been coordinated between ISIS and criminal gangs. They have had holding areas for them in Aleppo and Idlib provinces, where many were seized and it has taken them some time to be able to filter the Westerners through, collect them and push them into areas where there is less conflict. For them, the Westerners have a monetary value, they are treasure.”

The adviser fears that moving the prisoners east means “they are thinking of bundling them across the border into Iraq.”

A jihadist from Kyrgyzstan, a close associate of al-Chechen, is in charge of day-to-day security for the moving of Western captives, according to private security experts interviewed by The Daily Beast. “He has a scar on his face, 42 years old, 1.68 meters [5 feet 5 inches] tall,” says another security adviser.

The private security sources say that Syrian fighters aren’t allowed involvement with the Western prisoners and that many of the jihadists guarding them are Saudis, several from Najd region of the Gulf kingdom.