The danger zone has been extended another five miles (8km) around the mountain.
The Philippine Red Cross sent a warning of a “looming eruption” to its hundreds of thousands of followers on Twitter as the volcano continues to erupt ash.
The threat level was raised after an earthquake above magnitude 4 struck the Philippines on Friday and the volcano released a massive cloud of volcanic ash.
Those on the island have been urged to wear protective masks in the danger zone.
Philippine Red Cross tweeted: “Just in. Alert level 4 was raised over Mayon Volcano.
“This means extension of danger zone to 8 kilometres or more is recommended in the sector where the crater rim is low. The public is advised to wear protective masks and continue to be safe and vigilant.”
The epicentre of Friday’s earthquake hit 55 miles (88km) from the town of Baganga in Davao Oriental on the island of Mindanao, the US Geological Survey (USGS) said.
The earthquake hit at 2.26pm local time (6.26pm GMT) and was magnitude 4.7, the USGS said. But the Filipino volcanology institute said it was magnitude 4.
Four other earthquakes of around magnitude 2.5 have also been recorded across the country since midnight local time, according to the Philippines Institute of Volcanology and seismology (PHIVOLCS).
Baganga is located about 435 miles (800km) from Mayon volcano, which has been erupting for a week with red hot lava seen flowing down its slopes at one point.
Tens of thousands of evacuees have fled their home their homes after a “state of calamity” was issued in the Albay Province where the eruption volcano is located.
More than 34,000 people including 8,530 families have been evacuated to 32 evacuation centres across the country.
The UK Foreign and Commonwealth Office (FCO) said the volcano is demonstrating “low level activity” and warned an eruption may cause disruption to flights.
It added: “A ‘state of calamity’ has been declared in Albay province and local residents have been evacuated; if you’re planning on travelling to the region you should monitor developments through the institute and follow the advice of the local authorities.”