Bomb-making instructions and potential targets for "lone wolves in America" to attack were recently posted to an online message board sympathetic to the Islamic State militant group, also known as ISIS or ISIL, Vocativ reports.
The post — entitled “To the lone wolves in America: How to make a bomb in your kitchen, to create scenes of horror in tourist spots and other targets” — suggests targeting popular tourist destinations, such as New York's Times Square and the Las Vegas Strip, as well as train and subway stations throughout the United States.
The instructions appear to be similar to those previously published by the al-Qaida magazine Inspire and reportedly used by the Tsarnaev brothers to build pressure cooker bombs used in their attack on the 2013 Boston Marathon.
More from Vocativ's report:
The post describes the necessary bomb-making ingredients as being easy to obtain, easy to dispose of quickly and difficult to detect, even by police sniffer dogs. It goes into detail about how to pack the bomb with shrapnel-like pieces of metal for maximum effect, what kinds of casings to use depending on where the bomb will be deployed, how to ensure the safety of the bomber and where to place a bomb to create the most carnage. They also advise would-be bomb-makers on how to cover their tracks so as not to leave evidence on the device. The conversation initiated by the post appears to involve knowledgeable individuals with a strong desire to spread their know-how to others.
The posting appears to be similar to one that surfaced in an online publication last month calling for would-be terrorists to attack Times Square, Las Vegas casinos, oil tankers and military colleges with car bombs.
“This is a new world, if you will, or the evolving world of terrorism, and we’re staying ahead of it,” NYPD commissioner Bill Bratton told reporters on Tuesday. “We’ve been focused on it, and I believe that we are as prepared as any entity could be to deal with the threats.”
A representative for the Las Vegas Police Department did not immediately respond to a Yahoo News request for comment.
On Monday, New York City Mayor Bill de Blasio, New York Gov. Andrew Cuomo and New Jersey Gov. Chris Christie met with U.S. Homeland Security Secretary Jeh Johnson in Manhattan to discuss ways to secure the metropolitan region from a terror attack.
“As New Yorkers, we know our city is the No. 1 terror target,” de Blasio said.
Last week, President Obama said U.S. intelligence officials had "not yet detected specific plotting against our homeland."
"Our intelligence community believes that thousands of foreigners — including Europeans and some Americans — have joined them in Syria and Iraq," Obama said. "Trained and battle-hardened, these fighters could try to return to their home countries and carry out deadly attacks."
The same day, U.S. Homeland Security officials testified that the terror group did not pose an immediate threat of an attack inside the United States, but it does "have the ability to attack American targets overseas with little or no warning."
An NBC News/Wall Street Journal poll conducted earlier this month revealed almost half of Americans feel less safe than they did before 9/11.
A bomb expert told Vocativ that while the bomb-making recipe is nothing new, the chatter about possible targets is what's most worrisome.
“The techniques aren’t what worries me," the expert said. "The fact is they could start going on making these at home, and the forum seems to encourage and motivate would-be bomb makers."