Rescuers in Indonesia are searching for at least 400 people who have been reported missing, many believed to be buried under landslides, after cyclonic rains caused disastrous flooding nearly a week ago.

The death toll on the island of Sumatra has risen to more than 440, the government says.

Aid has been sent into affected areas by air and by sea, but some villages have yet to receive anything, and there are reports of people stealing food and water to survive.

Torrential rain and storms have devastated parts of Thailand, Malaysia, the Philippines, and Sri Lanka, affecting millions of people and leaving more than 900 dead across the region this month.

An exceptionally rare tropical storm, named Cyclone Senyar, caused catastrophic landslides and flooding in Indonesia, with homes swept away and thousands of buildings submerged.

People are missing in Aceh, North Sumatra, and West Sumatra, the National Disaster Management Agency said.

There are two cities that require full attention due to being isolated, namely Central Tapanuli and Sibolga, agency head Suharyanto was quoted as saying.

Some foreign aid has arrived, with Malaysia sending medical supplies to Aceh, one of the worst-hit provinces.

In Sungai Nyalo village, about 100km from West Sumatra's capital Padang, floodwaters had mostly receded, but homes, vehicles, and crops are coated in thick grey mud.

The authorities had not yet begun clearing roads, residents said, and no outside assistance had arrived.

Concerns have risen as reports emerge of looting in Sumatra, prompting police intervention to restore order.

In response to the communications crisis, tech billionaire Elon Musk announced he would provide free Starlink services to support emergency communications.

This devastating weather also impacted neighboring countries, including Thailand, where at least 170 people died, and Sri Lanka, where more than 330 fatalities have been reported due to floods and mudslides.

The extensive flooding has led to protests and public outcries in the Philippines regarding governmental corruption tied to flood control budgets, as many blame diverted funds for their vulnerable positions during these disasters.