Indonesians are facing a double threat from volcanoes. Mount Anak Krakatau (Child of Krakatoa) and Mount Kelud are both active. The ash inside Mount Anak Krakatau in Sunda strait continued to climb on Thursday (November 8) with smoke billowing from its crater. Volcanologists say an eruption might not happen immediately but tourists have been warned to stay away. The volcano was formed after its famous "parent" Krakatau had a massive eruption in 1883, triggering tsunamis and killing thousands of people. Indonesia's Centre for Volcanology and Geological Hazard Mitigation raised the alert on Mount Anak Krakatau to the second-highest level on Friday (November 2) after it threw up showers of ash. The volcano, which lies in the Sunda strait between the islands of Java and Sumatra, is about 130 km west of the capital Jakarta. Meanwhile in East Java Mount Kelud continues to threaten villagers living and working in its shadow. Though authorities have downgraded the alert status from its highest level two weeks ago fears of an imminent eruption still exist. And many villagers remain in evacuation shelters. An estimated 350,000 people live within 10 kilometres (six miles) of the volcano, which is about 90 km southwest of Surabaya, Indonesia's second-largest city and one of its busiest airports. The 1,731-metre (5,700-foot) volcano spewed ash about 500 metres into the air on Sunday. Some sand and stone miners, who depend on the mountain's boulders for building material, have remained in the shadow of the crater despite the danger, desperate to continue their work. Kelud, also known as Kelut, means "sweeper" in Javanese, a reference to the fact that when it erupts, it sweeps away everything in its path. When it last erupted in 1990 at least 30 people were killed, while about 5,000 died in 1919 when it spewed scalding water from its crater lake. Indonesia has the highest number of active volcanoes of any country, sitting on a belt of intense seismic activity known as the "Pacific Ring of Fire".