An investigation is under way after a lorry containing 20 people was discovered at a service station, police said.

Officers from Avon and Somerset are working with immigration officials following the discovery in on the A303 today.

An Avon and Somerset Police spokesman said: ''We stopped a lorry at a service station off the A303 at Southfields Roundabout at about 1pm, which contained a group of 20 people who are currently being treated by paramedics for possible dehydration.

''Their health and welfare is paramount as we try to piece together with the immigration authorities exactly what has happened.''

The discovery comes after the death of Meet Singh Kapoor, 40, from Afghanistan, who was found dead inside a container at Tilbury Docks in Essex on Saturday.

Members of the 34-strong group, including 13 children, survived the ordeal. They are all Afghan Sikhs from Kabul.