The problem of foreign jihadists in Syria blared across headlines again Monday after a disturbing video surfaced on YouTube showing British Muslims in the war-torn country savagely beating a man from a rival rebel faction. 

The video shows two men beating another with an iron bar. The force is so much that the bar breaks in half; during the flogging, the men call their victim a "kuffar," or unbeliever. 

Warning: the footage below contains graphic images. Viewer discretion is advised. 

Analysts say the two assailants are linked with the Al-Qaeda affiliated Al Nusra Front; the victim is from the Free Syrian Army (FSA), an allegedly "moderate" group whose goals are more localized. 

Another alleged British fighter, who the Telegraph UK notes is from London, posted a series of disturbing tweets describing torture and murder.

One features a photo of three men, tied up and blindfolded. "Got these criminals today. Insha'Allah [please G-d - ed.] they will be killed tomorrow. Can't wait for that feeling when you just killed someone," he tweeted.

He later posted a picture of a bloodied hand on his Facebook page, with the caption "My first time!," according to the daily.

Huffington Post UK notes that the news comes just after another British national has been linked to the fighting, and in a big way: Abu Sulaiman al-Britani, 26, was revealed to have played a major role in last week's prison bombing in Aleppo

Concern over foreign nationals continues

Monday's news provides yet another kernel of disturbing evidence regarding the scope of the foreign national problem in Syria, where a localized conflict has mushroomed into an all-out Islamic holy war between Shia and Sunni Muslims. 

Foreign nationals have been pouring into the embattled country to aid in both sides of the fighting, which has seen over 130,000 killed since 2011. Exact statistics vary wildly as to how many foreign citizens are currently fighting - with estimates as low as 7,500 and as high as 75,000  - but the mass exodus is enough for considerable concern about the potential for spillover. 

Last month, eyewitness accounts confirmed what analysts have long suspected: that Al Qaeda is training Western nationals in the war-torn country to bring fundamentalist Islam - and terrorism - back home with them. 

British Muslims, in particular, have been flocking to the fighting from all sectors of society. 

The Daily Mail reported in December that Al Qaeda officials have been suspected of reaching out specifically to British university graduates. Video footage which surfaced in December revealed that the young graduates fighting in Syria hail from all sectors of society - not just from London, but also from areas with regional accents. 

Britain's Muslim women have also been joining the rebel forces - marrying Islamists in the name of a global Jihad - as revealed last year.

More recently, 26 year-old Nawal Msaad was apprehended in Heathrow Airport as she tried to smuggle 20,000 euros ($27,364) to rebel forces in January.