The eruption produced loud thumping noises which could be heard from the volcano`s monitoring post about 6 km from the Tompaluan crater, Head of the BPBN Data and Information Center Sutopo Purwo Nugroho said.
The volcano spewed glowing lava and volcanic ash which moved in the northeasterly direction, he said.
"Right now there are still eruptions but they could not be observed as the volcano was covered by haze," he said.
The residents living 2.5 km from the crater should not carry out any activity, he said.
The volcano is now being put under the alert status.
"Until now there is no need for the residents to flee their homes," he said.
Lokon is one of Indonesia`s most active volcanoes and erupts on average every few years.
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