The Central American gang known as MS-13, which has been linked to a string of bloody murders in the US over the last few years, has been recruiting increasingly younger members and resorting to ever more violent methods, according to alarmed experts.

MS-13, or Mara Salvatrucha, was started nearly 20 years ago in Los Angeles after millions of immigrants from El Salvador came to the US after a violent civil war left more than 100,000 dead.

The criminal enterprise composed, mostly of El Salvadoran and Honduran youths, was the first to be designated by the FBI as an international criminal group.

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Alarm bells: Experts say the notorious Central American gang known as MS-13 has been recruiting increasingly younger members and resorting to ever more violent methods

With as many as 20,000 members in 46 states, the gang has expanded far beyond its initial roots. Members are accused of major crimes including murder, kidnapping, prostitution, drug smuggling and human trafficking.

One of MS-13's distinguishing features is its reliance on the machete - a broad, sharp and extremely durable knife that is ubiquitous in the farming communities of Central America - as the weapon of choice because of it is readily available, relatively cheap and can be used to inflict catastrophic injuries.

Experts studying MS-13 have recently noticed a shift in the demographics of the notorious gang and its modus operandi: they now skew younger and tend to be more ruthless.

Hector Silva, a former deputy chief of mission at the Washington embassy in El Salvador and current research fellow at the Center for Latin American and Latino Studies at American University in Washington, tells Newsday that brutality is considered a part of MS-13 members' identity, and they carry out acts of violence for the their own sake, not as a means to an end.

One of MS-13's distinguishing features is its reliance on the machete as the weapon of choice

MS-13's approach to murder is also distinct: people perceived as the gang's enemies are repeatedly stabbed or slashed with machetes and left out in plain sight to send a message to others.

One former member of the gang told the station WUSA9 in Virginia that the new generation of MS-13 are more extreme than their elders and more eager to uphold the group's motto, 'Kill, rape, control.'

‘The more vicious the crime is, the more they feel good about themselves. The more respect in their head that they get … even myself, I'm scared of them,’ said the man.

Northern Virginia Regional Gang Task Force Director Jay Lanham told the station the gang has been known to target children as young as fifth-graders.

Suffolk County Sheriff Vincent DeMarco seconded that assessment of the current state of MS-13, telling Newsday that he has witnessed gang members get younger and increasingly more desensitized to violence.

Attorney General Jeff Sessions traveled to Central Islip last month (pictured) and vowed to crack down on MS-13

‘Some of these are 16, 17, 18-year-olds who have no problem with hacking somebody up with a machete or knocking someone’s brains out of their head with a bat or a sledgehammer, and it doesn’t even faze them,’ DeMarco said .

In the past, law enforcement officials have been able to identify possible MS-13 members by their distinctive tattoos and certain items of clothing, like Nike Cortex sneakers, but the new wave of gangsters are trying to blend in by shunning overt signs of gang affiliation and using social media to conduct their business.

Many young members of the ultra-violent gang are living in the US illegally, having crossed the border as unaccompanied minors in the years following then-President Barack Obama's 2012 speech in which he announced a reprieve for DREAMers - people brought illegally to America as children under 16 before 2010 will be allowed to stay in the US.

Since the fall of 2013, the US has placed 165,000 undocumented Central American youths. Long Island has been a frequent landing spot. Suffolk County, which includes Brentwood and Central Islip, has gotten 4,500.

Over the past year, the two Long Island town have emerged as hotbeds of MS-13 violence.

Names of the dead: Michael Banegas (left) and his cousin Jefferson Villalobos (right), both aged 18, were identified by relatives as victims of a quadruple murder in Long Island

Jorge Tigre (left), 18, and Justin Llivicura (right), 16, were said to be among the friends discovered slaughtered in Central Islip Park in April

In April, four young men, between the ages 16 and 18, were found slaughtered and mutilated in a Central Islip park. So far, no arrests have been made in connection to those murders.

In March, 10 illegal immigrant members of the notorious gang - including one who was previously deported - were indicted in the savage killings of Nisa Mickens, 15, and Kayla Cuevas, 16, in Brentwood last September.

Suffolk Police Commissioner Timothy Sini said the injuries to the two girls 'were some of the worst wounds I’ve ever seen.'

As recently as last week, three suspected MS-13 members were arrested and charged with attempted murder stemming from a machete attack that has left a 19-year-old man with serious injuries in Westbury, New York.

Nisa Mickens, 15 (left), and Kayla Cuevas, 16 (right), from Long Island, New York, were ambushed by a carload of other teens on September 13 and killed

Miguel Alvarez-Flores (right) smiles and waves at news cameras in a Houston court , as the gang leader known as 'Diabolico' and his partner, 18-year-old Diego Hernandez-Rivera (left), faced charges of aggravated kidnapping and murder

The intensity and spread of violence connected to MS-13 has caught the attention of Attorney General Jeff Sessions, who traveled to Central Islip last month and vowed to crack down on the gang.

‘I have a message for the gangs that target our young people,’ he told a crowd of law enforcement officials and reporters assembled at the federal courthouse on April 28. said. ‘We are targeting you. We are coming after you.’

CBS New York reported Monday that in the wake of those developments, lawmakers in Albany are seeking to pass a series of measures that include stiffer sentences for gang activity and recruitment of members, and the addition of seven new felonies to the state's penal code.