In a dangerous sign that Pakistan-based Lashkar-e-Toiba (LeT) has expanded its tentacles in the United States, federal prosecutors on Friday announced to have arrested a New Yorker who was about to catch a flight to Pakistan to join the terror group.

While in Texas, the FBI charged a teenager with using social media to recruit people on behalf of the LeT.

Jesus Wilfredo Encarnacion (29), was arrested Thursday night at John F Kennedy International Airport (JFK Airport) as he was about to board an international flight with Pakistan being his final destination.

"Encarnacion allegedly attempted to travel to Pakistan to join a foreign terrorist organization and conspired with another individual to provide that organization with material support," said Assistant Attorney General John Demers.

Encarnacion, a.K.A. "Jihadistsoldgier", "Jihadinhear", "Jihadinheart" and "Lionofthegood," plotted to travel to Pakistan to join and train with LeT, which is infamous around the world for perpetrating the lethal 2008 Mumbai terror attacks and other atrocities, said US Attorney Geoffrey Berman.

A Manhattan resident, Encarnacion not only express a desire to "execute and behead people," he scheduled travel and almost boarded a plane so he could go learn how to become a terrorist, FBI Assistant Director-in-Charge William Sweeney Jr.

In the southern state of Texas, Michael Kyle Sewell, 18, was charged by the FBI with using social media to recruit people on behalf of LeT and send them to Pakistan for terrorist training.

The arrest of the New Yorker and the charges against the Texas teenager — who do not appear to be of South Asian origin as has been the case in previous such arrests – has set the alarm bells ringing among the law enforcement agencies in the US. The arrests have thrown the spotlight on issues of homegrown terrorism and radicalisation of American youths, a situation that authorities have dreaded post Mumbai-terrorist attack.