Two firefighting helicopters collided while fighting wildfires west of Athens on Sunday, Greece’s fire department said.
A search and rescue operation for the crews is under way in the Psatha area, it added.
Greek firefighters have been battling to control a huge wildfire that has destroyed over 100 homes northwest of Athens, while a fresh blaze forced evacuations on the popular tourist island of Kefalonia.
“During the aerial firefighting operation, two BELL helicopters, leased by the fire department, with a crew of two people each, crashed in the wider area of Psatha, Attica,” the Greek fire service said in a statement.
“The helicopters had taken off from the Elefsina military airport.”
Europe has been ravaged by wildfires this summer after a period of record-breaking heatwaves and little rain – conditions that scientists say have been exacerbated by climate change.