Jakarta: Indonesia's Mount Soputan volcano on the quake-and tsunami-hit island of Sulawesi erupted Wednesday, spewing volcanic ash 4,000 metres into the air.
The state disaster agency warned people to stay at least four kilometres (two and a half miles) away but said there was no need to evacuate for the time being.
Images showed an eruption visible for miles around, with a cloud of ash climbing in a large vertical column with a mushroom-shaped top.
Soputan is around 1,000 kilometres from the town of Palu where a 7.5 magnitude earthquake triggered a tsunami that lashed the coastline killing almost 1,400 people.
Meanwhile, the death toll in Indonesia's twin quake-tsunami disaster passed 1,400 Wednesday, with time running out to rescue survivors and the UN warning of "vast" unmet needs.
National disaster agency spokesman Sutopo Purwo Nugroho said the number of dead had risen to 1,407 across four areas around the ravaged seaside city of Palu, and 519 bodies had been already buried.
Authorities set a tentative deadline of Friday to find anyone still trapped under rubble, at which point -- a week after this devastating double disaster -- the chances of finding survivors will dwindle to almost zero.
Government rescue workers are focusing on half a dozen key sites around the city -- the Hotel Roa-Roa where up to 60 people are still believed buried, a shopping mall, a restaurant and the Balaroa area where the sheer force of the quake turned the earth temporarily to mush.
At least 150 people are unaccounted for beneath the rubble, officials said.
According to the UN's humanitarian office almost 200,000 people need urgent help, among them tens of thousands of children, with an estimated 66,000 homes destroyed or damaged by the 7.5-magnitude quake and the tsunami it spawned.
Despite the Indonesian government urging foreign rescue teams to "stand down" because the crisis was in hand, residents in hard-hit, remote villages like Wani in Donggala province say little help has arrived and hope is fading.
"Twelve people in this area haven't yet been found," Mohammad Thahir Talib said.
"In the area to the south, because there hasn't been an evacuation we don't know if there are bodies. It's possible there are more," the 39-year-old said.