The plume coming from the Taal volcano, south of the capital Manila, stretched about 1km (0.6 miles) into the sky.
Rumbling sounds and tremors were also reported around Taal - the Philippines' second-most active volcano - on Sunday.
Authorities raised the alert level, warning that a "hazardous eruption" was possible within weeks.
The Philippine Institute of Volcanology and Seismology also warned residents living nearby of a possible "volcanic tsunami", while flights were suspended at Manila's international airport because of the volcanic ash.
