Many homes in Gunung Rajo village on Sumatra island were buried when mud gushed down from surrounding hills late on Thursday, said Mr Rustam Pakaya of the government's Disaster Crisis Center on Friday.

The bodies of a 28-year-old woman and her children - aged 1, 3, 5 and 8 - have been recovered, he said.

Villagers have joined in the rescue efforts, he added, some using farm tools to search for survivors. An excavator also has arrived at the scene.

Seasonal downpours cause dozens of landslides and flash floods each year in Indonesia, a vast chain of 17,000 islands where millions of people live in mountainous areas or near fertile flood plains.

Parts of west and east Java island also were inundated on Friday following days of heavy rain, but there were no immediate reports of fatalities. -- AP