Padang, W Sumatra, Sept. 21 -- Mount Marapi in West Sumatra erupted twice on Sunday, with the second eruption occurring at 4:36 p.m. local time, following an earlier eruption at 1:28 p.m., the Marapi Volcano Observation Post (PGA) reported.

"The second eruption was recorded, but the ash column was not visible due to cloud cover," PGA official Teguh Purnomo said in Padang.

Seismic instruments measured the second eruption with a maximum amplitude of 7.3 millimeters and a duration of 53 seconds.

Marapi remains at Alert Level II (Waspada), the second-lowest on Indonesia's four-tier scale.

The Geological Agency's Center for Volcanology and Geological Hazard Mitigation (PVMBG) continues to prohibit activity within a three-kilometer radius o...