MADRID, July 26 (Xinhua) -- Spain is enduring one of its most destructive wildfire seasons in recent years, with massive blazes sweeping through the Madrid region and neighboring Avila, forcing tens of thousands of people to evacuate or remain indoors.

The fires have ravaged thousands of hectares across Spain, with the government declaring a national emergency.

Wildfires continued to burn across central Spain on Saturday. Authorities warned that strong winds and low humidity continue to hamper firefighting efforts despite cooler overnight temperatures.

Madrid's regional president Isabel Diaz Ayuso described it as the "worst fire in the history of the region."

According to the latest official figures, around 91,000 people have either been evacuated or ordered to stay indoors across the Madrid region, the province of Avila and parts of Toledo. The fires have destroyed or damaged approximately 45,000 hectares in the neighboring provinces of Madrid and Avila.

"The situation is complex," Interior Minister Fernando Grande-Marlaska said on Saturday, adding that it "has not been a positive day" for firefighting operations amid "extremely difficult" weather conditions.

The fires in Madrid and Avila are part of a broader wave of wildfires affecting Spain this summer, with major blazes also burning in the eastern province of Castellon after earlier deadly fires in Almeria claimed 13 lives this month.

Since the start of the year, nearly 130,000 hectares have burned across Spain, according to the European Forest Fire Information System.

Thousands of firefighters, soldiers, police officers and civil protection personnel have been deployed across the affected areas. The Military Emergency Unit continues to play a central role in protecting communities and critical infrastructure while supporting regional firefighting teams.

Spain has also activated the European Union Civil Protection Mechanism, under which Greece and Italy each offered two Canadair firefighting aircraft, together with an additional support aircraft. Italian aircraft had already joined suppression operations over Madrid and Avila on Saturday.

International assistance has also included 33 Greek and 14 Italian emergency personnel deployed to support Spanish emergency services, the military and security forces. Meanwhile, Portugal sent 129 firefighters and emergency personnel, along with 41 vehicles, including fire engines, command vehicles, bulldozers and ambulances, to reinforce firefighting efforts.

The rapid spread of the wildfires has been fueled by a combination of extreme weather conditions. Javier Armeteros, Madrid delegate of Spain's State Meteorological Agency, said the fires developed under conditions that firefighters commonly refer to as the "30-30-30 rule" -- temperatures above 30 degrees Celsius, relative humidity below 30 percent and wind speeds exceeding 30 kilometers per hour.

According to Armeteros, temperatures in the affected area exceeded 32 degrees Celsius, relative humidity dropped below 30 percent, and wind gusts reached between 50 and 60 kilometers per hour.

The intensity of the blaze has also forced firefighters to change their tactics. Jose Maria Bermudez, spokesperson for the Forest Rangers Corps in Madrid, said emergency crews could not launch direct attacks on the head of the fire because doing so would be "going straight to death." Instead, they have focused on protecting populated areas and critical infrastructure whenever conditions allowed.

Israel Naveso, spokesperson of Madrid firefighters' union, said the current emergency was the result of "a perfect storm" of factors, including abundant vegetation following a wet winter, three heatwaves in six weeks and strong winds, which together created ideal conditions for multiple fast-moving wildfires.

The wildfire threat is unlikely to ease soon. According to the latest national wildfire risk assessment by meteorological authorities, large parts of eastern, southern and central Spain remain at high or extreme risk of wildfires, indicating that weather conditions continue to favor the ignition and rapid spread of fires across much of the country.