JEMBLUNG, Indonesia (AFP) - Rescuers searching for more than 80 people missing after a landslide in Indonesia deployed bulldozers and excavators on Sunday to battle their way through roads strewn with debris to the site of the tragedy, officials said.

At least 20 people have been confirmed dead after torrential downpours triggered the landslide hitting Jemblung village in central Java late Friday, National Disaster Management Agency spokesman Sutopo Purwo Nugroho said.

Hundreds of rescuers were digging through the mud with shovels and their bare hands in a desperate hunt for any survivors.

"I am very worried," a sobbing Sutinem, whose 12 family members including her children were buried in the landslide, told AFP. The 45-year-old, who like many Indonesians goes by only one name, said so far only the body of her mother had been found.

She was not at the village when the landslide hit as she was working in west Java.

"I was shocked to see that my village was flattened to the ground... I pray that the government will find them quickly," she said.

"We are trying our best to look and evacuate those still buried. It's a big challenge because we are still using manual tools and the affected area is very muddy," Banjarnegara district military commander Edi Rahmatullah told reporters.

Authorities were using heavy equipment to clear a three-metre high pile of fallen trees and rubble on the main road leading to the site of the tragedy.

"Today the search for survivors will be carried out using heavy excavation equipment. The landslide has blocked road access since yesterday," Nugroho said. "Part of the road has now been cleared," he added.

Around 1,250 rescuers, including police, soldiers and volunteers, were involved in the search operations.

Nugroho said 20 people were killed and 88 remained missing on Sunday, more than 24 hours after the landslide swept down a hillside in the village.

"Those who died were trapped under soil," Nugroho said.

Fifteen people were injured, including 11 seriously, and 577 people were evacuated to temporary shelters, he added. "Many of (the survivors) were injured from being hit by debris and are being treated in the hospital," he said.

Nugroho said survivors were in need of food, blanket, medicine and clothes.

President Joko Widodo was travelling from the capital Jakarta to Central Java's provincial district of Banjarnegara on Sunday to meet with survivors. "I am in grief over the landslide that struck Jemblung village," he wrote on his Facebook page, urging the Central Java governor Ganjar Pranowo to evacuate victims.

"Landslides can be a lesson to us, on the importance of maintaining environmental balance," he added.

Landslides triggered by heavy rains and floods are common in tropical Indonesia during the rainy season. The national disaster agency estimates around half the country's population of 250 million lives in areas prone to landslides.

The vast Indonesian archipelago is one of the most natural-disaster-prone nations, and is also frequently hit by earthquakes and volcanic eruptions.