Powerful flash floods killed at least five people and left four others missing in Indonesia on Thursday.

Torrents of muddy water battered homes after heavy rain caused the Brantas River to swell on the slopes of Mount Arjuno, in Batu City, East Java Province.

The Batu City Regional Disaster Management Agency (BPBD) reported that the victims had been swept away by the strong deluge. Several people were rescued but others are still missing.

'There are five villages that were affected by the flash floods,' said Achmad Choirur Rochim, an official at the Batu City Regional Disaster Management Agency.

Water overflowed onto roads and a number of vehicles were swept away by the flood currents. In addition, one house was damaged when the water carried mud and branches from the mountain.

Rochim said material losses were still being calculated.

He added: 'Emergency operations have been carried out, but for tonight the focus is on seeking help as well as cleaning and restoring vital infrastructure and roads covered in mud.'

Indonesia and other countries in Southeast Asia such as Malaysia, the Philippines and Thailand are at the peak of their tropical monsoon rainy season, which lasts until late November. Soaring temperatures reaching 35 degrees Celsius are often followed by powerful tropical storms with thunder, lightning, rain and flash floods which cause rivers to flow faster and become dangerous.

Seasonal rains often cause flooding and landslides in Indonesia, where millions of people live in mountainous areas or near fertile flood plains.

Forecasters believe that heavy rain will continue in Indonesia until February, partly because of a La Nina weather pattern.