More than 100 wildfires stretched thousands of firefighters to the limit in northern Portugal on Wednesday, in the worst spate of fires in recent years.

Thousands of firefighters tackling deadly wildfires in central and northern Portugal had largely doused the flames in the Aveiro district, one of the worst-hit, as of Thursday morning, and were focusing on a dozen blazes still raging elsewhere.

With several blazes burning since 14 September, Portugal has recorded the highest total estimated emissions for the month of September in 22 years of CAMS data. That includes both carbon emissions and harmful particulate matter pollutants like PM10 and PM2.5.

More than 100 wildfires are stretching thousands of firefighters to the limit in northern Portugal. The country’s worst spate of fires in recent years is blamed for seven deaths since they spread out of control over the weekend.

Firefighters tackling deadly wildfires in central and northern Portugal had doused the flames in the Aveiro district, one of the worst-hit, as of Thursday, and were focusing on eight large blazes still raging elsewhere.

More than 100 forest fires have been raging in the north of Portugal since last weekend. The regions of Aveiro, Porto and Viseu are particularly affected. Thousands of firefighters are battling a 13-kilometer-long fire front.