- Group consists of 14 adults and one child
- Driver assisting police with inquiries
In a statement, Surrey Police said the group included five children and came from Iraq, Iran and Syria.
Police say the driver called authorities after hearing a loud banging coming from inside the vehicle.
Surrey Police officers closed the main access road into the gas station at Clackett Lane. The driver had parked at the gas station while the people were detained.
According to the British Home Office, 11 males, including "five who claim to be minors", were arrested.
One of the men was taken ill at the scene and transferred to hospital, where the Home Office says he remains.
The five other men have been passed onto immigration officials for assessment while the juveniles will be met by social services.
A family of four, including two children, was also encountered at the scene. The Home Office said they will be interviewed by immigration officials.
In September, Britain announced it was building a four-meter (13 foot) high wall as part of a £17 million ($23 million) deal
struck with France in an effort to block migrants from crossing the English Channel.