Wildfires caused by arsonists or thunderstorms and fanned by a heatwave and strong winds wreaked destruction across southern Europe, burning homes and forcing thousands of residents and tourists to flee.

Firefighters have spent days battling blazes in Greece, Portugal, Spain and elsewhere. Forecasters said temperatures could pass 111 degrees in some places on Thursday.

Red flag warnings now cover parts of Oregon, Washington and California. In Oregon and California, crews are battling flames that are burning thousands of acres. Along the West Coast, heat alerts remain in effect for 11 million people.