Thousands of villagers were evacuated after a volcano on an island in eastern Indonesia started spewing lava and hot clouds, officials said Friday. There were no reports of casualties.

Mount Karangetang, one of the country's most active mountains, has been rumbling for weeks.

Lava and hot ash avalanched 750 yards down the volcano's slopes on Thursday, its second eruption since July 17, said Saut Simatupang, chief researcher at the government's volcanology agency.

Nearly 4,000 people were evacuated from five villages, said Iskandar Gobel, a North Sulawesi provincial official, and police in the area said more would likely leave in coming days.

Indonesia, the world's largest archipelago, is prone to seismic upheaval due to its location on the so-called Pacific "Ring of Fire," an arc of volcanos and fault lines encircling the Pacific Basin.

Karangetan is on Siau, part of the Sulawesi island chain, which has not been affected by a recent string of natural disasters in the country.

A massive earthquake off Java triggered a tsunami earlier this month that left 600 dead and a temblor on the same island in May killed 5,800. Mount Merapi, also on Java, has seen heightened activity in recent months.

CountryWatch: Indonesia