JAKARTA (XINHUA) - A flight alert was issued as Sinabung volcano in North Sumatra province in the eastern part of Indonesia erupted on Saturday (Aug 8), the National Volcanology Agency said.

The 2,475m-high volcano located in Karo district spewed a column of volcanic ash up to 2km high. The ash tends to head for the east of the crater, the agency said in a statement.

Planes have been prohibited to fly in the airspace above the hot cloud areas, as a volcano observation notice for aviation with the orange level has been issued since Friday.

The volcano has the potential to erupt further, along with the release of hot clouds.

Heavy rain of volcanic ash is threatening the areas located in the slope of the volcano, and the volcanic materials may be spread further by the wind to the areas located out of the slope.

Still, there is no heightened potential danger around the volcano, whose alert level is at the second highest.

No-go zones have been declared in the radius of 3km from the crater, and 4km for areas situated from the east to the north of the crater, as well as 5km for areas located from the south to the east of the crater.

Sixteen people were killed and thousands of others were forced to flee home when Mount Sinabung erupted in 2014.

Mount Sinabung is one of the 129 active volcanoes in Indonesia, a vast archipelagic nation of over 17,500 islands.