Two men are in hospital after 16 people were discovered in the back of a lorry in Sussex in “exceptionally hot” conditions.

The people, believed to be migrants from countries including Iraq, Syria and Iran, caught the attention of motorists at 9.20am by waving from the lorry on the A22 in East Grinstead.

The driver came to a halt at a bus stop after motorists flagged him down.

A total of 13 men, two women and a child were found in the vehicle. Two men were taken to hospital suffering from dehydration.

The remaining people were taken to the nearby Trinity Methodist Church and provided with water and medical assistance.

The people were found on one of the hottest days of the year in the UK so far, with temperatures reaching 29C.

Sgt William Keating-Jones, of the Crawley Neighbourhood Response Team, said: “Our priority was for the welfare of the occupants who were in the back of the lorry. The vehicle was exceptionally hot and it was important we reacted quickly.

“This was a great multi-agency response to a potentially life-threatening situation, with emergency services, immigration officials, volunteers and even local residents all pulling together.”

The 63-year-old driver, of no fixed address, was arrested on suspicion of facilitating illegal immigration and remains in police custody.

The incident is being led by the Home Office, which said the migrants will be processed “in line with immigration rules”.