Scorching heat hampered efforts to contain 20 major wildfires across Spain on Sunday, prompting the government to deploy an additional 500 troops from the military emergency unit to support firefighting operations.

Firefighters in Spain, Portugal and Greece battled ongoing wildfires Friday, an important religious holiday in all three countries, as persistent hot, dry conditions challenged efforts to contain the blazes.

Spain on Friday warned of "very high or extreme fire danger in most of the country," as firefighters there continue battling 14 blazes in temperatures up to 104 degrees Fahrenheit.