Indonesian President Joko Widodo yesterday travelled to South Kalimantan to witness what he described as possibly the worst flooding in 50 years in the area.
At least 15 people have died and nearly 40,000 displaced as the country comes to grips with yet another natural disaster while grappling with surging Covid-19 cases.
Ten cities and regencies in a province battered by heavy rain since earlier this month have been affected.
The floods had inundated 24,379 houses and forced 39,549 residents out of their homes as at Sunday, said Disaster Management Agency (BNPB) spokesman Raditya Jati.
The provincial government declared a state of emergency last Thursday and rescuers have distributed rubber boats and other basic necessities such as food, mattresses and blankets.
In pouring rain, Mr Joko visited flooded villages, witnessed overflowing rivers and inspected damaged bridges. He was also briefed on efforts to cope with the situation.
"This is the biggest flood in South Kalimantan province in maybe more than 50 years. The rainfall has been very high for almost 10 consecutive days," said the President, popularly known as Jokowi.
"I would like to express my deep sorrow for the victims who died."
Severe flooding has also occurred in at least two other provinces.
In Manado, the capital of North Sulawesi province, six people were killed and 500 have been forced out of their homes in floods and landslides caused by heavy rain and unstable soil conditions as at yesterday, said BNPB.
Earlier this month, 36 people were killed in floods and landslides in Sumedang regency, West Java.
Natural disasters are common in Indonesia, and floods happen yearly during the rainy season, which is expected to continue until mid-February.
Quakes and volcanic eruptions occur frequently in the sprawling archipelago that sits on the intersection of several tectonic plates and within the Pacific Ring of Fire.
Last Friday, a powerful and shallow 6.2-magnitude quake rattled West Sulawesi province, killing 84 people. As at yesterday, it has left over 19,000 homeless in the worst-hit regencies of Mamuju and Majene. More than 900 people were injured, including 253 seriously.
Photos and footage distributed by BNPB showed damaged roads, collapsed buildings and victims trapped under rubble.
Aid - including tents, bottled water and ready-to-eat food - has already been distributed to survivors.
In an effort to curb the spread of Covid-19 in the country - the worst in South-east Asia, with more than 907,000 cases and around 26,000 fatalities - rapid tests were carried out at evacuation camps, and vulnerable groups were kept away from young people, a lower-risk group.
Last Saturday, Mount Semeru in East Java erupted, sending hot air and ash clouds cascading 4.5km down its crater.
Villagers living on the slopes of the active volcano and near rivers were warned to stay alert as rainfall could trigger cold lava floods.
Yesterday, Mount Merapi in Central Java also erupted, releasing hot clouds 1km from the crater.
In response to the catastrophic South Kalimantan floods and devastating Sulawesi quake, the Singapore Red Cross (SRC) has committed an initial $150,000 to support relief and recovery operations.
The SRC will also be launching a public fund-raising appeal following the double disasters.