Legazpi, Philippines ? The restive Mayon volcano showed fresh deposits of searing gas, rocks and ash as scientists warned Tuesday that more destructive lava flows likely would occur.

Lava flowing down Mayon already has destroyed wide swaths of farmland and permanently altered the terrain near two villages, volcanologist Ed Laguerta said.

Scientists have said the 8,077-foot volcano near Legazpi may be gearing up for an explosive eruption. Mayon started to spew ash and sulfuric dioxide last month.

Nearly 44,000 residents have been evacuated from 32 villages.

Mayon, a popular tourist attraction because of its nearly perfect conical shape, is one of the Philippines’ 22 active volcanos. Its most violent eruption in 1814 killed more than 1,200 people, many of whom sought refuge in a church.