A volcano erupted on Wednesday morning on the same Indonesian island as an earthquake and tsunami which killed more than 1,400 people.
Authorities warned planes about volcanic ash in the air, but said there was no immediate threat to human life.
On Wednesday, the official toll from the earthquake and tsunami rose to 1,407.
National disaster agency spokesman Sutopo Purwo Nugroho said 519 of the bodies had been buried.
Mount Soputan in North Sulawesi province spewed ash 6,000 metres (19,700 feet) into the sky on Wednesday morning. No evacuations were immediately ordered.
A government volcanologist said it was possible the eruption was accelerated by the 7.5 magnitude earthquake in Central Sulawesi on Friday.
"It could be that this earthquake triggered the eruption, but the direct correlation has yet to be seen as there had been an increase in the Mount Soputan activity," Kasbani, the head of Indonesia's Vulcanology and Geology Disaster Mitigation agency, told online news portal Tempo.
Mr Kasbani said volcanic activity had increased at Soputan since August but began surging on Monday.
Nazli Ismail, a geophysicist at the University of Syiah Kuala, Banda Aceh on Sumatra island, stressed there was no concrete evidence to show they were linked.
"People talk about the butterfly effect. The concept is that when a butterfly flaps its wings, it can cause a catastrophe," he said. "So it is possible for the earthquake to trigger the volcano eruption, but it's not conclusive. This needs to be further investigated."
Mr Nazli said the Soputan volcano eruption was not surprising as Indonesia sits on the seismically active Pacific "Ring of Fire," and Soputan is one of the most active volcanoes on the island.
Soputan's eruption status was raised from an alert to standby, 4 kilometres (2.5 miles) from the summit and up to 6.5 kilometres to the west-southwest. Standby status means the public should avoid the area nearest the volcano and have masks available in the event of ashfall.
Planes were warned of the ash clouds because volcanic ash is hazardous for engines.
The earthquake in Central Sulawesi set off a tsunami and devastated several communities.
Indonesia is an archipelago of more than 250 million people. Government seismologists monitor more than 120 active volcanoes.
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