Staff based at Houston's William P Hobby airport have been trained to spot the signs of sex trafficking in time for this year's Super Bowl.

A team of specialists, named Airline Ambassadors, have been training staff who work in the airport on how to spot the warning signs of trafficking, as well as how to help the sex trafficking victims to safety.

One hundred staff members volunteered to take part in the session ran by the group, in which crews were advised to look for passengers who look ashamed, nervous or frightened while on a flight, appear bruised, or look like they are travelling with someone who is not their parent or relative.

Related to Super Bowl

Although there are not any direct links between human trafficking and the Super Bowl, there tends to be a larger demand for sex trafficking when a large sporting event takes place, says Nita Belles, director of the anti-trafficking group In Our Backyard.

"When you have a male-dominated kind of attendance, then you will have additional trafficking in coming in," Belles said.

Houston is particularly prone to sex trafficking, as it is part of an easy access corridor between the US and South America, and has large and busy airports. This makes it one of the largest human trafficking destinations in the US, says kxan.com, an Austin-based news channel.

Expressing his support for the project, Mayor of Houston, Sylvester Turner said: "We don't want to be known as the hub in this region for human trafficking."

US Immigration and Customs Enforcement arrested 2,000 human traffickers nationwide last year, says the NBC report.

Around 771,000 people attended the Super Bowl in 2016. The sporting event, which will see the New England Patriots and the Atlanta Falcons do battle for the title, will take place at Houston's NGR stadium.

It is expected that more than 100 million people will tune in to watch the annual sporting event from home.