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.

More than 5,000 personnel are battling a number of wildfires, the authorities said, and the prime minister called it an “extremely difficult weather situation.”

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.