Concerns are rising that the volcano in the Philippines, which has been spewing ash and smoke kilometers into the sky this week, could erupt at any moment.
For more on this and other news around the world, let's turn to our Yoon Jung-min.
Jung-min, it seems people there are bracing for a major eruption.
That's right, Mark. Since the Taal volcano pumped a massive cloud of ash into the sky on Sunday, there are growing signs a "hazardous" eruption is still possible.
Frequent earthquakes, fissures or cracks have been detected around the volcano, which could indicate a major eruption is imminent.
Seismologists also say an eruption could potentially trigger a tsunami.
The Philippine Institute of Volcanology and Seismology said the surface activity of the Taal's main crater has eased slightly, but there's still magmatic and hydrovolcanic activity.
Also, fissures have been spotted on the ground where the volcano is located.
"What the tremors mean is that there are magma rising to the surface. With the tremors are reports of fissures in areas and towns surrounding Taal volcano, which is associated most likely to the rise of magma, causing pressures to faults or fissures, triggering earthquakes and causing more cavities."
The authorities are maintaining an alert level 4 out of maximum of 5 since the first eruption began last weekend.
Level 4 means a "hazardous eruption is imminent or may occur within days or hours".
If the level is raised another notch, it means a hazardous eruption is already in progress.
So far, more than 24-thousand people have been evacuated from nearby areas.
Schools and businesses were closed across Manila on Monday due to clouds of ash covering the city.