|One Direction star Niall Horan is flanked by personal
security guards as he goes shopping
on Sunset Plaza on November 7, 2012
The 'Kiss You' hitmakers' management have reportedly hired a team ex-secret service agents whose previous assignment was protecting the American leader to escort the group as they travel across America for their 'Take Me Home' world tour from June.
A source said: "They will be protected by some of the best security personnel America has to offer.
"There is significant concern that the group will be greeted by mobs of thousands of girls, which is too much for the normal team to handle. To make matters worse it is the US school holidays too."
As well as the ex-secret service agents, the boy band - consisting of Niall Horan, 19, Zayn Malik, 20, Liam Payne, 21, Harry Styles, 19, and 21-year-old Louis Tomlinson - will also be closely watched by three ex-military servicemen who served during the Iraq wars.
The impressive security detail will be tasked with fending off throngs of screaming teenage fans as they escort the 'Little Things' singers at all times, including flights, hotels, concert venues and on their tour bus.
Last week, the band were mobbed by excited fans hoping to catch a glimpse of them outside of their hotel in Paris, France.