The identities of two accomplices of the infamous Islamic State terrorist known as "Jihadi John" have been confirmed, according to multiple media reports Sunday.  Jihadi John, whose real name was Mohammed Erwazi, was an English-speaking member of the terror group known as ISIS, and he was known for his participation in many propaganda beheading videos.

Erwazi and his accomplices, revealed to be London-born Aine Davis and Alexanda Kotey along with a fourth unidentified man, were nicknamed "The Beatles," or John, Paul, George and Ringo, by their foreign captives for their British accents. The group beheaded at least five captives, including journalists James Foley and Steven Sotloff, as well as 18 soldiers of the Syrian army.

Foreign fighters have become an increasingly important component of ISIS’ network, as the group seeks to depose Syrian President Bashar Assad and establish a strict Sunni Muslim "caliphate" over the Middle East. At least 700 U.K. residents have attempted to join ISIS, according to an August report in British newspaper the Telegraph, making the nation one of the top three sources of foreign fighters for the extremists.

All three men became radicalized in London and grew to be close friends before they traveled to Syria, some time around 2014. It has not been confirmed whether they traveled alone or separately to join ISIS. A U.S.-led drone strike on Raqqa, Syria, in November 2015 killed Erwazi, who was 27 at the time.

Kotey, 32, who is half Greek Cypriot and half Ghanaian, grew up in a neighborhood of West London, near Erwazi, that has a reputation as a breeding ground for Islamic radicalization. Kotey was not raised Muslim and converted to Islam after falling in love with a Muslim woman around 2003, Buzzfeed News reported. “He grew up with my sons. He was lovely and a really quiet boy,” a neighbor told Buzzfeed News.

Less is known about Davis, who reportedly attended the same London mosque with Kotey and Erwazi, ITV News reported. Kotey and Erwazi reportedly became increasingly radical, often speaking in defense of suicide bombings and other terror tactics. Both men eventually became part of an jihadist group known as the London Boys, who helped plan the 2005 London subway bombings that left 56 dead, including the perpetrators. U.S. and British defense officials have not determined whether Kotey has been killed in airstrikes, the Washington Post reported.