SCENIC Taal Volcano emitted mud-laden geysers, prompting scientists to raise a low-level alert Friday.
But officials at the Philippine Institute of Volcanology and Seismology said there was no danger of an immediate eruption.
The 311-meter (1,026-foot) Taal, about 75 kilometers (45 miles) south of Manila, draws many tourists because of its location in the middle of a bluish-green lake.
A new mud geyser spewed water rising about 50 centimeters (20 inches) above the surface, the institute said in a statement.
It also recorded 10 quakes in the last 24 hours, compared to 48 in the previous week.
Taal has occasionally triggered seismic activity and geysers, and erupted mildly in 1977, causing no casualties or damage. A strong eruption in 1965 killed about 200 people living nearby.