Greek police have found 41 people alive in a refrigerated truck in a discovery that has underscored the extraordinary risk migrants are prepared to take to get into Europe.

At least a third were found to have trouble breathing, and seven were rushed to a nearby hospital with respiratory problems.

The vehicle’s refrigeration system had broken down by the time the truck was stopped at a motorway toll station outside the city of Xanthi in north-east Greece and its passengers, of apparent Afghan origin, were discovered.

“A police operation is under way but we believe the lorry entered the country from Turkey,” said Lt Col Theodoros Chronopolous, a police spokesman. “Discoveries of this sort are rare but happening more frequently mainly because migrants want to avoid the islands.”

The truck’s driver, a 40-year-old Georgian national, was arrested, Chronopolous said. The lorry is believed to have raised suspicion partly because it had no markings or livery.

The discovery comes after the deaths of 39 people, all believed to be Vietnamese nationals, who were found by UK police in the back of a refrigerated lorry in Essex.

Two male lorry drivers appeared in court in the UK and Ireland last week facing manslaughter and human trafficking charges. Eight people were arrested on Monday in connection with the incident in Vietnam, according to state media outlets.

Greece is in the midst of a resurgence of asylum seeker arrivals from Turkey with numbers not experienced since the height of Europe’s refugee crisis in 2015 when more than a million people, mostly from Syria, landed on the shores of Lesbos, Samos and other Aegean isles.

More than 35,000 men, women and children are in Greek island camps where deplorable conditions are the subject of mounting concern and condemnation from human rights groups. Most of the asylum seekers are believed to want to reach other parts of Europe.

Chronopoulos said it was thought the lorry was headed inland towards Thessaloniki. “Where the migrants were ultimately destined is not clear,” he said. “Their first stop was Greece, their second elsewhere in Europe. Traffickers and migrants are taking ever greater risks.”