The Indonesian volcano known as the "Child of Krakatoa" spewed ash and smoke, prompting warnings of a possible eruption, a government volcanologist said Saturday.

The mountain in the Sunda Strait, 80 miles west of Jakarta and between the islands of Java and Sumatra, formed after the giant Krakatoa eruption of 1883 that killed tens of thousands of people and was the largest explosion in recorded history.

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"Activity at Anak Krakatoa increased yesterday and there were several small eruptions," said Surono, a leading government volcanologist who, like many Indonesians, uses one name. "We have upgraded the alert level to the second highest."

Anak Krakatoa, which means "Child of Krakatoa," is the third volcano to become active in recent weeks in Indonesia, a sprawling nation of more than 17,000 islands.

The country has about 150 volcanos along an arc of fault lines called the Pacific "Ring of Fire."

Krakatoa's massive 1883 blast, heard nearly 2,000 miles away in Australia, sent pyroclastic surges of gas and burning ash which, combined with a tsunami, wiped out 165 villages and killed at least 36,417 people.

It destroyed two-thirds of the island of Krakatoa.