Los Angeles, Sep 20 (IANS): Two huge wildfires, the Windy and KNP Complex fires, burning around the Sequoia National Forest and the Sequoia National Park in US state California, spread to 18,075 acres (73.1 square km) and 21,777 acres (88.1 square km) respectively on Sunday.

A statement released by the Sequoia National Park on Saturday said the KNP Complex reached the Four Guardsmen in the Giant Forest. The Giant Forest is the home for over 2,000 giant sequoias, including the General Sherman Tree - the world's largest tree by volume, Xinhua news agency reported.

The Four Guardsmen is a colonnade of four giant sequoias located near the south gate of the forest.

But the statement added that "fuel removal efforts by firefighters, combined with structure wrap applied by crews to the base of the iconic sequoia trees, successfully protected these national treasures."

The blazes swirling around California's giant sequoia trees prompted more evacuations Sunday as they spread toward communities surrounding the forests, while the authority warned that the fires would remain active throughout the night.

The historic sequoia trees in Sierra Nevada mountains, which are thousands of years old and grew to be hundreds of feet tall, were increasingly threatened by drought, climate change and extreme fire.

Last year, the Castle Fire wiped out 10 per cent of the world's native sequoias, according to the National Park Service.