The blaze on mountain slopes 3,000 feet above sea level was one of many that hit Vietnam this week, Vietnam News reported. Unusually high temperatures have turned many wooded areas into tinder.
The fire in Hai Van Pass 20 miles north of Da Nang began in a eucalyptus forest, rangers said. About 500 firefighters, rangers and soldiers were sent in to try to contain it.
Phan Van Rong, deputy head ranger in Lien Chieu section, said the terrain made the fire hard to reach and to combat, particularly because it was located near an ammunition depot left over from the Vietnam War.
Smaller fires have destroyed acres of eucalyptus, sandalwood, acacia and other trees, officials say. Temperatures have topped 100 degrees Fahrenheit in many areas this week.