The grim discovery, announced by the fire brigade on Tuesday afternoon, was made in a rural area south of the village of Avantas.
“Given that there have been no reports of disappearances or missing residents from the surrounding areas, the possibility that these are people who entered the country illegally is being investigated,” the fire brigade said.
The broader Evros region is a popular route for migrants crossing the river by the same name from Turkey into Greece.
“Searches throughout the entire area where the fire broke out are ongoing,” the fire brigade said.
It came as hundreds of firefighters struggled on Tuesday to control major wildfires that had been burning out of control for days in northeastern Greece and on Tenerife in Spain’s Canary Islands, with strong winds fanning the flames and prompting evacuations of villages and a city hospital in Greece.
Hot, dry and windy conditions have seen dozens of wildfires break out across Greece, with the most severe entering its fourth day and encroaching on the northeastern port city of Alexandroupolis.
A massive wall of flames raced through forests toward Alexandroupolis overnight, prompting authorities to evacuate another eight villages and the city’s hospital. The flames turned the sky over the city and across the region red, hiding the sun as choking smoke and swirling flecks of ash filled the air.
On Monday, two people died and two firefighters were injured in separate fires in northern and central Greece. The fire risk level for several regions, including the wider Athens area, was listed as “extreme” for the second day on Tuesday.
Authorities banned public access to mountains and forests in those regions until at least Wednesday morning and ordered military patrols.
In Spain’s Canary Islands, firefighters battled to control a wildfire burning for a week on the popular tourist destination of Tenerife. More than 12,000 people have been evacuated from their homes and nearly 15,000 hectares (37,000 acres) of pine forest and scrubland have been burned.
Meanwhile large parts of Spain were under alert for wildfire risk due to a heatwave that sent temperatures spiking over 38C in many areas.
Greece suffers destructive wildfires every summer. Its deadliest wildfire killed 104 people in 2018, at a seaside resort near Athens that residents had not been warned to evacuate. Authorities have since erred on the side of caution, issuing swift mass evacuation orders whenever inhabited areas are under threat.