JAKARTA (AFP) - Eight miners were killed and at least three more were missing after a landslide on Monday (Dec 18) on the slopes of a volcano on the Indonesian island of Java, officials said.

An avalanche of sand and rock cascaded down the slopes of Mount Merapi in Central Java about 10am (11am Singapore), burying a group of miners digging through the rocks and sand.

"The landslide happened suddenly and immediately buried the miners," disaster mitigation agency spokesman Sutopo Purwo Nugroho said in a statement.

It was not raining when the incident occurred, but the almost vertical incline of the slope made it slip-prone, Nugroho said.

Another eight miners were injured in the accident and have been taken to a nearby hospital for treatment.

Rescuers were using heavy machinery to search for survivors, the local disaster mitigation agency said.

Mount Merapi, an active volcano near the city of Jogjakarta, is the site of widespread illegal sand mining. The high-quality volcanic sand is used to make cement.

Officials have repeatedly warned locals against mining in the area because of its sheer slope and recent heavy rainfall.

Landslides are common in Indonesia, especially during wet season between October and April, when rain lashes the country.

Last month, at least 11 people died in heavy flooding and landslides in Pacitan, East Java.