10 photos of ‘volcano within a volcano’ in Philippines that can turn into a tsunami

• Taal volcano, one of the world’s smallest volcanoes that started spewing lava. It has the potential to cause a volcanic tsunami.
  
• The volcano started emitting huge amount of ash and smoke into the sky on sunday.
  
• As many as 16,700 people were evacuated after the ash fall reached the capital Manila.
  
• Taal volcano is located within a middle of a lake, and is part of a volcanic chain that extends through the western region of the island of Luzon.
  
  

Taal volcano, one of the world’s smallest volcanoes that started spewing lava in Philippines. This could spiral into a “hazardous eruption” that can occur within hours or days -- and probably lead to a volcanic tsunami.

Volcano tsunamis are often caused by tectonic movements in the ocean from volcanic activity.

As many as 16,700 people were evacuated after the ash fall reached the capital Manila. The Philippine Institute of Volcanology and Seismology (PHIVOLCS) raised the threat level from 1 to 4 on a scale of 5 after an increase in activity within Taal's crater resulted in the billowing of a huge plume of smoke that reached heights of around 1 km.

An alert level of 4 implies that a dangerous eruption could be imminent and that there is a risk of a tsunami.