Mayon in Albay spewed thick smoke and ashes as high as five kilometers this morning.
The activity began at 8:50 am.
Lava was flowing from the crater at about 5 am.
It lasted for about 30 minutes.
Residents within the nine-kilometer extended danger zone could hear rumbling sounds from the volcano.
This prompted many of them to flee from their homes to evacuation centers.
The Philippine Institute of Volcanology and Seismology (PHIVOLCS) describes the event as phreato-magmatic eruption wherein the volcano is releasing pyroclastic materials mixed with water.
It says, the eruption yesterday was much stronger than today.
Volcanologist Ed Laguerta says, Mayon is just in the beginning stage of eruption.
Alert level 4 remains in effect.
PHIVOLCS will only raise the alert level to 5 once the eruptions become continuous.
Meanwhile, classes in Legazpi City in Albay and in many affected municipalities are cancelled today.
The operations of the Legazpi City airport has been temporarily shut down.
The Provincial Disaster Risk Reduction and Management Council (PDRRMC) says, the number of evacuees has reached 40,000.
Some of them are residents of Legazpi City who had previously sought shelter and had gone home last Thursday.