The government has stockpiled food supplies in case of evacuations after Mount Bulusan in Sorsogon province emitted ash and smoke six times in recent weeks, Malacañang said on Sunday.
In addition to the emergency food packs, authorities are closely watching communities near the volcano, Communications Secretary Herminio Coloma said.
The latest emission came Sunday, an ash and steam column that rose 150 meters into the air and drifted toward four villages in Bulusan town.
"The government continues to monitor the behaviour of Mount Bulusan… so we can safeguard the welfare of about 34,000 affected residents in 22 villages and five towns," Coloma said.
The Philippine Institute of Volcanology and Seismology (Phivolcs) said that so far, the emissions have been caused by groundwater mixing with hot rocks inside the 1,565-meter volcano.
These "phreatic eruptions" have sent ash and smoke into the air, covering the volcano's slopes and nearby towns, said Winchelle Ian Sevilla, the officer heading a Phivolcs team monitoring Mount Bulusan.
Sevilla said that as long as people stay out of the 4-kilometer "danger zone" around the volcano, they would not be hurt by any falling rocks.
Aircraft have also been warned to avoid Bulusan in case of a sudden ejection of ash.
Despite the activity, Sevilla said there was no sign magma was rising inside the volcano, indicating there was no impending eruption of lava.
On June 16, Bulusan spewed "old ash" that had no trace of magma, indicating there was no possibility of a full-blown eruption, according to Eduardo Laguerta, Phivolcs resident volcanologist.
Laguerta said the Phivolcs recorded three volcanic quakes over the past 24 hours.
Laguerta said 41 tremors were also recorded, but all had no felt intensities.
On Friday, Laguerta said the phreatic, or steam-driven, explosions were not significant compared to past eruptions of the volcano. Even if the volcano spewed a kilometer-high grayish steam and ash plume cloud, it was still considered a "small explosion," he said.