The Lokon volcano erupts near Tomohon on the Indonesian island of Sulawesi.

The Lokon volcano erupts near Tomohon on the Indonesian island of Sulawesi. Photo: AFP

More than 4600 people have been evacuated since an Indonesian volcano erupted on Thursday and its alert status was placed on the highest level, an official said.

Mount Lokon on Sulawesi island spewed grey ash up to 800 metres high early today as it continued to rumble.

"The evacuees are placed in six shelter points. No one has died because of the direct impact of the eruption," disaster management agency spokesman Sutopo Purwo Nugroho said.

Villagers take shelter inside a school building after they fled their homes on the slope of Mount Lokon in North Sulawesi.

Villagers take shelter inside a school building after they fled their homes on the slope of Mount Lokon in North Sulawesi. Photo: AP

"The disaster management agency has assisted them by disbursing 300 million rupiah ($A32,840.57) of emergency funds, logistics, equipment and personnel," he said.

The 1580-metre Mount Lokon is one of the most active volcanoes in Indonesia. It erupted in 1991, killing a Swiss tourist.

The Indonesian archipelago has dozens of active volcanoes and straddles major tectonic fault lines known as the "Ring of Fire" between the Pacific and Indian oceans.

The country's most active volcano, Mount Merapi in central Java, killed more than 350 people in a series of violent eruptions last year.

AFP