These heartbreaking images capture the astonishing lengths refugees will go to to illegally enter Europe.
The photos posted by Spanish police show the moment border police found a man in his 20s squeezed behind a car dashboard, trying to enter Spain's North African enclave of Melilla, the Daily Mail reported.
Officers said three vehicles were searched in Beni-Enzar, Morocco, in the space of three hours on Saturday.
The pictures also showed a stowaway cramped into an engine compartment.
Another illegal migrant was behind a car's rear seats, and a fourth in a dangerous position in a dump truck, where they were in danger of being crushed.
The migrants, including a 15-year-old girl, were rescued from their cramped surroundings and two of the men, aged 20 and 21, had to receive medical treatment.
Border police said the men were showing signs of suffocation, disorientation and pain in the joints.
Three males, all Moroccan nationals and aged 19, 30 and 31, were arrested on suspicion of people smuggling. They each drove Moroccan registered cars of different brands.
It follows other attempts to cross into Melilla.
Two men were found sewn into mattresses in January, while a 12-year-old boy was discovered behind a dashboard in 2017.
Morocco is the main departure point for undocumented migrants going to Spain and the enclave of Melilla has become a regular flashpoint for African migrants in recent years.
At the Strait's narrowest point, the distance between North Africa and continental Spain is 7.7 nautical miles, around 14km.