These stones were dropped preparing to block the flow of mud. Photo: AP.

Hot mud and toxic - enough to fill 50 Olympic swimming pools - has flowed up from the crater during the past 9 months, at least 11,000 people forced to flee their homes. 4 villages and 25 factories have been buried under thick mud near 9 meters.

Cement balls are strung, each weighing nearly 247 kg, will be dropped from a scaffolding into the mud volcano on Java island, starting from today. If successful, this project will reduce to 70% of the sludge is currently a system of dams moved to a nearby river and out to sea.

Mud cracks usually appear along the geological belt loosely flowing underground Like Indonesia, the world's largest archipelago. Many different opinions on the causes of the appearance of this mud flow - the largest mud flows are recorded here - but experts agree that it can flow in the next few years.

Some experts have speculated that cracks appeared in the technical fault gas extraction PT Lapindo Brantas Corporation, and the government has declared the group will pay about 420 million dollars to compensate for damage.