JAKARTA, Dec. 31 -- Mount Sinabung, one of the most active volcanoes in Indonesia, erupted again midnight Tuesday, the strongest since September, spewing hot ash up to 7,000 meters high along with lava and forcing more evacuation, an official said.

Hot lava burst forth with flames from the crater and slid off the southeast slope of the volcano, leading the authorities to warn all residents nearby to evacuate, Sutopo Purwo Nugroho, spokesman of disaster management and mitigation agency, told Xinhua by phone.

"The people are asked to evacuate, especially those living on the southeast side of the mountain as hot lava and ash keep bursting to the direction," said Sutopo.

The rumbling volcano started minor eruption on Monday afternoon and erupted intermittently for seven times, according to the spokesman.

He added that there were no casualties.

The 2,457-meter Mount Sinabung in Karo district of North Sumatra has rumbled to life since September after being quiet for 400 years, but it went into overdrive in November, forcing the authorities to extend evacuation zone to within a radius of 5 km from 3 km.

The Mount Sinabung is among the 129 active volcanoes in the vast archipelago country, which is prone to seismic upheaval as it lays on the Pacific "Ring of Fire" encircling the Pacific Ocean.