"Five minutes apart — at 21.30 MSK (18:30 GMT) and 21.35 MSK — Be-200 planes of the Russian Emergencies Ministry landed at the airport of the city of Leiria," the ministry’s representative said.
According to the Russian ministry, Russian pilots are conducting preparatory work and will shortly start their operation at tackling the fires across Portugal.
Portugal has been experiencing wildfires for several days after temperatures rose to 35 degrees Celsius (95 degrees Fahrenheit). Some 6,000 people, including volunteers, are taking part in daily efforts to contain and extinguish the fires, with the Portuguese military also involved.
The wildfires that gripped Portugal's Madeira Island claimed the lives of at least three people and destroyed some 100 buildings as well as prompted thousands of people to evacuate.