A tropical cyclone which hit Indonesia's main island of Java has triggered severe flooding and landslides which left 19 dead, an official said Wednesday.

Landslides claimed 15 lives in east and central Java, while four others perished in floods unleashed by Cyclone Cempaka.

"Thousands of homes, hectares of agricultural land and public facilities are also flooded," said Sutopo Purwo Nugroho, spokesman for Indonesia's disaster agency.

The destruction from the cyclone comes as the rumbling Mount Agung volcano on the neighbouring resort island of Bali threatens to erupt, forcing tens of thousands to flee their homes.

Cempaka is expected to move away from Indonesia later Thursday, but more flooding and landslides could follow in its wake, the agency said, adding that it urgently needs blankets, clothes and inflatable boats.

Torrential rain since Monday has caused rivers in the area to overflow, forcing the evacuation of more than 4.000 villagers, he said.

The rain, triggered by a tropical storm, caused floods and landslides in 20 districts of East Java and in Klungkung in Bali, Sutopo said.

The extreme weather will continue to hit the Indonesian islands of Java and Bali, the spokesman added, warning people to be prepared for floods, landslides and tornados.

The agency said it urgently needs blankets, clothes and inflatable boats for affected areas.

Seasonal rains cause frequent floods in Indonesia, where many of the 260 million people live in mountainous areas or fertile, flood-prone plains near rivers.

In September last year almost 30 people died in devastating floods and landslides in Garut, West Java.