Jakarta, All flights around Indonesia’s Anak Krakatau volcano were re-routed and the alert level was on Thursday raised to the second-highest possible, days after the volcano triggered a tsunami leaving over 400 dead.
The alert was raised from Level 2 to 3 on a scale of 4 and the exclusion zone around the volcano was extended to a 5-kilometre radius, according to the Indonesian National Board for Disaster Management (BNPB).
“People and tourists are prohibited from carrying out activities within a 5-kilometre radius of the crater peak of Mount Anak Krakatau,” the agency’s spokesperson Sutopo Purwo Nugroho said.
Air traffic control agency AirNav Indonesia said it was closing flight routes because the volcanic ash Krakatau was spewing meant the e-situation was on “red alert”, the BBC reported.
According to an AirNav operations manager between 20 and 25 flights were affected, including some international flights to and from Australia, Singapore and the Middle East.
He said that the disruption was likely to be minimal, although passengers may experience longer journeys and aircraft may need more fuel because of the diversions.
Authorities said that Anak Krakatau has become increasingly active with what are known as Strombolian eruptions — short-lived, explosive blasts of lava — being emitted.
Residents that live on both sides of the strait were being told to stay away from beaches due to fears of another tsunami.
Strong winds were carrying thin volcanic ash spewed by the volcano to neighbouring areas, but authorities said this was “not dangerous” and were advising residents to wear masks and goggles.
The BNPB said that there may be a new crater hole under the sea and that explosions were ongoing, with eruption sounds heard several times a minute.
The Anak Krakatau volcano recorded a small-scale eruption on December 22, the agency said, adding that satellite images showed it caused a collapse of its southwest side, which upon falling into the sea triggered the tsunami that hit the coasts of Java and Sumatra islands.
Rescue teams have been working against the clock to find survivors of the disaster, which according to latest official data left at least 430 dead and 1,495 injured, with 159 people still missing.
About 22,000 people were displaced and forced to take shelter in evacuation centres as the authorities also ordered a complete evacuation of small islands of the area.
Indonesia sits on the Pacific Ring of Fire, an area of great seismic and volcanic activity that is shaken every year by some 7,000 earthquakes, most of them moderate.
