MANILA, Philippines - The Philippine Institute of Volcanology and Seismology (Phivolcs) raised Tuesday the alert level of Taal Volcano from Level 1 to Level 2.

Allan Loza of the Phivolcs Taal Volcano Observatory said the volcano has exhibited increased seismic activity such as volcanic earthquakes and tremors since the last week of April.

Phivolcs said a total of 32 high frequency volcanic earthquakes was recorded in the past 24 hours and the size of recorded earthquakes has been increasing. A low frequency type volcanic earthquake was also detected last June 2, 2010.

"Initial result of precise leveling survey conducted yesterday at the southeast side of the volcano island showed further inflation by 3.0mm, " it said.

He said steaming activities at the northern and northeast sides of the main crater occasionally intensified, sometimes accompanied by audible hissing sounds.

Phivolcs said the recorded high frequency volcanic earthquakes could be the result of active rock fracturing associated with magma intrusion beneath the volcano.

Considered one of the most active volcanoes in the world, Taal remained at alert level 1 since 2004. Alert Level 2 means that the public is discouraged to to go up the main crater located at Daang Kastila due to hazardous steam-driven-explosions as well as buildup of toxic gases.

Alert Level 2 also means that the volcano is experiencing magmatic intrusion that, according to Phivolcs, may lead to an eruption.

Phivolcs reiterates that the volcano island is a permanent danger zone and permanent settlement within the area is strictly prohibited.