JAKARTA -- Indonesia's Mount Ibu volcano erupted on Tuesday, spewing thick columns of grey ash five km (three miles) into the sky, the volcanology agency said, but there were no immediate reports of evacuations.

The volcano on the eastern island of Halmahera erupted at 5:36 a.m. for about two minutes, said Heruningtyas Desi Purnamasari, an official of the PVMB agency, with all activities barred within seven kilometres (4.4 miles) of the crater.

"The volcano is recently active because there is an intense magma movement," Heruningtyas said, adding that its alert status was at the highest level, where it has been since May 16.

Clouds of grey ash billowed into the sky from the crater in video images provided by the agency, PVMB, following a smaller eruption on Monday.

They are the latest in a series since May that spurred authorities to evacuate seven nearby villages, although Tuesday's incident forced no new evacuation, the BNPB disaster agency said.

Indonesia straddles the so-called "Pacific Ring of Fire," an area of high seismic activity where multiple tectonic plates meet.

Last month, the eruption of the Ruang volcano in North Sulawesi spewed incandescent lava, forcing the evacuation of more than 12,000 people.

More than 60 were killed after flash floods and cold lava flow from Mount Marapi, one of the most active volcanoes in the province of West Sumatra, inundated several nearby districts following torrential rain on May 11.