HELSINKI (AP) — Sweden says it has mobilized all available resources to put out dozens of wildfires raging across the country.

The Swedish Civil Contingencies Agency said Wednesday that two Canadair CL-415 water-bombing planes on loan from Italy joined the firefighting efforts that included helicopters from Norway.

Swedish public broadcaster SVT says an estimated 40 wildfires are burning mostly in Sweden, mostly in the central and western parts of the country, but also in the Arctic north.

Thousands of people have been warned to remain inside with the windows shut to avoid breathing smoky air.

The Nordic region of Europe has experienced an intense heat wave in the past week. Temperatures reached over 32 degrees Celsius (90 F) throughout Finland, Norway and Sweden. The weather also has been dry.