Lava has spilled from a Philippine volcano that's also sending up columns of ash now coating farmland and towns after a nearly two-week eruption.

More than 74,000 people are staying in emergency shelters after fleeing the danger zone around Mount Mayon. Officials are worried the eruption may last months.

The Philippine Institute of Volcanology and Seismology said Friday lava eruptions have been intense but sporadic over the previous 24 hours. It measured ash plumes rising up to 5 kilometers (3 miles) high and detected 15 volcanic earthquakes as well as emissions of sulfur dioxide.

GPS and other measurements also continue to indicate a swelling of the mountain surface consistent with magma rising and creating pressure. Scientists have said the lava eruptions may be relieving that pressure, which then rises again.