The Mayon volcano in the Philippines is showing signs of becoming clogged with lava and scientists say it could erupt at any time.
The ABC reports the volcano has been oozing lava and emitting huge quantities of ash and toxic gas for weeks, and its activity has increased in recent days.
Thousands of people have been evacuated from areas surrounding the volcano.
Philippine government vulcanologist Ed Laguerta says a powerful eruption could take place at any time.
The official alert level remains at four - one short of a full eruption.