ISIS tweets threats attacks at Heathrow, LAX and JFK airports on 4th of July

Islamists claiming allegiance to Islamic State have issued a threat against Heathrow, LAX and JFK airports, warning that one of them would be targeted over the July 4th weekend.
The account said that attacks would be carried out on planes 'flying from Heathrow to the US' and warned that 'there will be a device placed in either Heathrow, LAX or JFK airports.'
The threat was revealed by SITE Intelligence Group - the world's leading non-governmental counterterrorism organization - on its website.