File photo of volcano in Sulawesi of Indonesia.

A volcano in North Sulawesi province of central Indonesia erupted earlier Sunday, but there is no evacuation, head of the country's volcanology agency named only Surono said in Jakatar.

Mount Soputan located some 60 km from Manado, capital of the province, started a small eruption at around 02:00 a.m. local time Sunday, spewing over 1,000-meter high hot ash, then it was followed by a big eruption at 06:03 a.m. local time by spewing over 6,000 meters high ash, the head of the agency told Xinhua by phone.

The agency has declared a dangerous zone with a radius of 6.5 kilometers, said Surono.

"So far, there is no evacuation because the closest area where people live is about 8 kilometers from the mount," he said.

Agus Budianto, head of monitoring and search at the agency also said that based on the character of the 1,874-meter high Mount Soputan and the history of its eruption, the authorities may still not need to order an evacuation, Budianto told Xinhua by phone from the headquarters of the agency in West Java on Sunday.

Budianto said the ash spew toward western part of the island, which does not disturb flight routes.

"We have told the airport in Manado city to be alert. We will give a warning should the ash direction change to the south (the route of flights)," he said.

The official said the second eruption might be the biggest and predict the next eruption may be weaker.

The agency has raised the alert level of the volcano to the second top level at 23:00 p.m. local time Saturday, said Budianto.

Mount Soputan is one of Indonesia's active volcanoes whose number is about 129, according to the National Volcanology Agency.