JAKARTA - Mount Sinabung volcano in Karo district, Indonesia's North Sumatra province erupted earlier Thursday, spewing a column of ash two km to the sky, a disaster agency senior official said.

The eruption took place at 02:45 am Jakarta time followed by tremors with ash sliding two km to the east and southeast, and 1.5 km to the south of the crater, said spokesman for the national disaster management Sutopo Purwo Nugroho.

"But the eruption did not leave casualty and trigger fresh evacuation," he told Xinhua in a text message.

On Wednesday, the volcano also erupted, spreading ash by up to 1.5 km high, said Sutopo.

Mount Sinabung has been on top alert since July 2, 2015 with no-go zone of seven km in the south, southeast and east of the crater, according to him.

Mount Sinabung is one of Indonesia's 129 active volcanoes.