LISBON, Portugal (AP) — More than 1,000 firefighters are battling a major wildfire in central Portugal for a third day that has already injured 31 people.

The country's Civil Protection Agency says 321 vehicles and five water-dumping aircraft are also at the blaze Monday. The flames have raced through thick woodlands in the Castelo Branco district, 200 kilometers (about 125 miles) northeast of Lisbon, the capital.

Cooler night temperatures helped emergency services get the upper hand over the fire, but authorities say they expect heat and winds to build in the afternoon. Forests are tinder-dry after weeks with little rain.

Summer wildfires are a common occurrence in Portugal, where poor forest management and climate change make woodlands vulnerable.

In 2017, at least 106 people were killed by wildfires in an especially difficult year for Portugal.