PHOTOS: Indonesia's Mount Sinabung spewing ash kilometres-high into the air

Indonesia’s Mount Sinabung has erupted again, sending an ash plume two kilometres into the air.

The volcano blanketed Medan, the provincial capital of North Sumatra – and Indonesia’s third-largest city – in ash, forcing residents to wear masks.

Photo: Yusdharmanto/ Facebook.

Flight operations at the city airport, as well as other daily tasks, have not been hindered by the ash fall.

An alert status for the volcano was raised to the highest level early this month.

Mount Sinabung is one of about 130 active volcanoes in Indonesia, which is prone to activity due to its proximity to the Pacific “Ring of Fire.”

It has sporadically erupted since 2010, after being dormant for 400 years. Here’s a look at it erupting in 2013.

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