JAKARTA—Indonesia’s Semeru volcano on Java island erupted early on Sunday spewing a two kilometers (1.24 miles) high ash column, prompting authorities to warn people to stay away from the eruption range. Earlier this month, the eruption of Semeru, Java’s tallest mountain, ejected ash clouds and pyroclastic flows that killed at least 46 people and left several missing, while thousands were displaced. On Sunday, the early morning eruption resulted in dense white and grey ash clouds, according to Indonesia’s Center for Volcanology and Geological Hazard Mitigation (PVMBG). The agency warned nearby residents not to conduct any activities within a five kilometers (three miles) radius of the eruption centre and to keep a 500 meter (1,500 feet) distance from riversides due to risks of lava flow. PVMBG also told people to not conduct any activities within 13 km (eight miles) southeast of the eruption centre. With 142 volcanoes, Indonesia has the largest …