LISBON, Portugal (AP) — The Latest on wildfires in Europe (all times local):

4:10 p.m.

Portugal's Interior Ministry says police have arrested 91 people — a record number — this year on suspicion of being behind a spate of wildfires. Those detained are suspected of either deliberately starting fires or contributing to them out of neglect, which is also against the law.

The Civil Protection Agency says 86 people have been injured, seven of them seriously, in wildfires over the past week.

Wildfires are a common annual occurrence in Portugal, where woodlands are poorly kept and mostly elderly people live in the countryside. But this year is beating records, with 141,000 hectares (350,000 acres) of forest charred through July — a 485 percent increase on the annual average of the previous 10 years, according to the Institute for Forests and Nature Conservation.

1:25 p.m.

Portugal's government is taking the rare step of decreeing a state of public calamity before a forecast rise in temperatures that authorities fear will worsen a spate of wildfires.

Prime Minister Antonio Costa's office says in a statement that he will meet with heads of the emergency services, including the armed forces, on Friday to prepare for a weekend rise in temperatures to around 40 C (104 F).

Decreeing a public calamity allows authorities to mobilize emergency assets and quicken reaction times.

Portugal has been fighting woodland blazes for weeks, including one in June that killed 64 people.

The government said Thursday the most worrying areas are in the north and center of the country, as well as western parts of the Algarve on the southern coast.