A helicopter fighting wildfires in central and northern Portugal crashed on Sunday, the civil protection agency said, adding that the pilot was feared dead.
"The Ecureuil helicopter was attacking the fire at Cabril when it crashed shortly before 1:00 pm," Patricia Gaspar, a spokeswoman for the agency, told AFP.
About a hundred firefighters were battling the blaze near Cabril, a village in the northern Castro Daire municipality.
It is one of a string of fires that have led the government to declare states of emergency in several regions.
The mayor of Castro Daire, Fernando Carneiro, said the helicopter, belonging to a private Portuguese aviation firm called Everjets, struck power lines before hitting the ground.
Media reports said the craft then caught fire and exploded, killing the pilot.
This summer has seen a record number of fires in Portugal, and Interior Minister Constanca Urbano de Sousa has blamed arsonists and human negligence for most of them.
Blazes in mid-June near Pedrogao Grande in central Portugal killed 64 people and injured more than 250.
The country has received reinforcements from abroad, including a Canadair water bomber from Morocco, three similar planes from Spain and three Super Puma helicopters from Switzerland.