JAKARTA: Indonesia's Anak Krakatau volcano erupted twice in just over one hour on Friday, spewing volcanic ash as high as 3,000 metres (9,843 feet) into the air, according to country's volcanology agency.
The volcano erupted at 7.46am (0046 GMT) local time on Friday then again 62 minutes later. Time-lapse images shared by the agency showed the widening of a large cloud that was billowing from the volcano and moving southwest.
The 157-metre (515.09-ft) high Anak Krakatau, located in Indonesia's Sunda Strait between Java and Sumatra islands, has erupted more than 10 times since March this year. The nearest settlement to the volcano is 16.5 kilometres (10.25 miles) away.
Authorities have issued the second-highest alert level, Oktory Prambada, an official at the volcanology and geological agency told Reuters, adding there had been no evacuation order but tourists and residents were advised not to approach or climb the volcano.
Indonesia sits on the Pacific "Ring of Fire" and has 127 active volcanoes, according to the volcanology agency.
A December 2018 eruption of Anak Krakatau triggered an underwater landslide that set off a tsunami in Banten, West Java province and Lampung province that killed at least 430 people.
As of Friday, four Indonesian volcanoes were at the second-highest alert level, including Anak Krakatau, Merapi in Central Java, Semeru in East Java, and Karangetang in North Sulawesi.
Anak Krakatau, or the child of Krakatau, emerged from Krakatau volcano, which famously erupted in 1883 and killed more than 36,000 people in a series of tsunamis.