A feared serial killer in Moscow may actually be an Islamic State (Isis)-inspired terror group doing Jihadist training exercises, emerging reports claim.

The incredible reports could force police to re-ascribe the deaths in Russia's capital city of 14 people, who were previously thought to be victims of one deranged individual.

But it now appears the dead may actually been killed by a gang of budding recruits for Islamic State - the infamous terror group fighting in Syria and Iraq.

Unconfirmed reports from Russia suggest the killings were "tests" to carry out for different members of the gang – both men and women.

They were said to be responsible for the brutal killings of 14 motorists on streets just outside Moscow, who were tricked in to getting out of their vehicles before the killer struck.

Sharp objects were placed on the road and when the victim got out to investigate, they were ambushed and shot dead.

It was previously thought the slayings were the action of a lone predator, possibly similar to the so-called 'Chess Board' killer, Alexander Pichushkin - who killed dozens of victims in a Moscow park.

But if true, this case would make truth look stranger than fiction by pinning the blame on IS fanatics, desperate to join the group's jihad in the Middle East.

The story has come to light following the violent death of the alleged leader of the gang.

The 33-year-old, known at present only as 'Usmanov,' was killed by police in a shoot-out in a village named Udelnaya, in the district of Ramenskiy.

Russian TV station 360 degrees reported the incident and Reuters has reported the potential mistake in classification of the 14 deaths. Russia's Interior Ministry is yet to comment.