Lava has been flowing from the dome of the volcano for 10 days, with clouds of ash ejected up to 2km into the sky.
Nearly 50,000 people have been evacuated from the area surrounding the volcano, but many have reportedly tried to return home for the Christmas holiday despite the continued danger.
Christmas is the biggest annual festival in the predominantly Roman Catholic Philippines.
In an effort to keep residents from returning, troops have been ordered to enforce an extended 10km no-go zone around the volcano and have imposed 24 hour curfew.
Mayon, the most active of 22 volcanoes dotted across the Philippines, has been rocked by hundreds of increasingly powerful earthquakes in recent hours, suggesting a major explosion could be imminent.
However, volcanologists studying the rumbling mountain say that at the same time the volcano may yet calm down or settle into a more moderate eruption phase.
Meanwhile residents living outside the evacuation area are reporting health problems from the clouds of volcanic ash ejected from the volcano.
Villagers have said the ash is stinging their eyes and irritating their skin.
Medical officials have warned that the tiny ash particles could cause respiratory problems or skin diseases and have advised residents to cover their mouths and skin when they go outside.