ISIS threatens to blow up either Heathrow, LAX or JFK

ISIS has threatened to blow up either one of three major airport in the world: London's Heathrow, Los Angele's LAX or New York's JFK on July 4 (America's Independence Day)

The threat was made through a Pro-ISIS Twitter  account. Bear in mind that this threat comes three days after there was a bomb attack on Turkeys Largest Airport on Tuesday Night; which the death toll has since risen up to 50.

They warned that the attacks will be carried out through planes which will be flying from Heathrow  to either LAX or JFK.

The threat was revealed by SITE Intelligence Group - the world's leading non-governmental counterterrorism organization - on its website.

The group is directed by founder Rita Katz, who has tracked and analyzed global terrorism and jihadi networks for nearly two decades.

She is well-recognized as one of the most knowledgeable and reliable experts in the field and has received special recognition from FBI Director Robert Mueller for her 'outstanding assistance to the FBI in connection with its investigative efforts.'

New Security  Measures at JFK after Tuesday's Istanbul attack.

This comes as authorities in the US brace themselves for a weekend of traffic chaos as it was revealed that up to 43 million people will be travelling across the country for Fourth of July weekend.

Huge firework displays will take place across the nation, as well as concerts and family fun days.

On Thursday, the FBI said there are no specific or credible security threats against the United States known to law enforcement heading into the Fourth of July weekend.

'However, law enforcement and members of the public must remain vigilant. ... The FBI asks members of the public to maintain awareness of their surroundings and to report any suspicious activity to law enforcement,' an FBI spokeswoman said in a statement to Reuters.

An internal briefing document shared with government officials and seen by Reuters called for the Department of Homeland Security to be on alert following recent attacks, such as the mass shooting in Orlando, Florida, on June 12, and calls from Islamic State supporters for attacks in the Western Hemisphere.

An instance of a Crowd at the International Terminal in London Heathrow 

The absence of known threats does not ensure safety.

There were no threats known before the Orlando massacre, in which a gunman who pledged loyalty to Islamic State killed 49 people and wounded 53 more in the deadliest mass shooting in modern U.S. history.

The document said mass transit systems are particularly vulnerable to attack. It also said an attack over the U.S. Independence Day holiday would garner media attention that would further Islamic State's propaganda efforts.

There was no mention in the FBI's statement or in the document of the gun and bomb attack that killed 44 people at Istanbul's airport on Tuesday.

In the wake of the attack experts have called for a worldwide rethink on airport security.

The demands reflect the increased likelihood of terror attacks throughout Europe, with seven countries across the continent considered 'high risk' by the British Foreign and Commonwealth Office.

NYPD outside of JFK

Indeed, the June 28 attack in Turkey hit one day after the US State Department issued a travel warning to American citizens about the increased terror threat in the Turkey - and to avoid the south of the country altogether.

The current threat level in Turkey is currently classified as an emergency alert.

And at the beginning of June, the State Department issued a Europe-wide travel alert, specifically concerning the European Soccer Championship currently underway in France and for the Catholic Church's World Youth day in Poland this July.