KUPANG, Indonesia (AFP) -- Thousands of people have fled areas near deadly landslides in Indonesia fearing heavy rain could trigger a new disaster, as the rescue operation intensified on Tuesday, officials said.

Some 2,500 anxious villagers on Flores island, where landslides and flash floods on Saturday killed at least 36 people, had sought safe shelter away from their homes, relief worker Johny Erasmus told AFP by telephone.

He said some went to Ruteng, a town on a key road leading to the villages the landslides overwhelmed some 35 kilometers (21 miles) away.

The road was blocked but has been cleared, allowing aid and machinery to reach the disaster site and intensifying the search for the 38 still missing.

"Access was re-established Monday afternoon and relief has now reached the affected areas," said Joos Mono, a rescue coordinator in Ruteng.

Teams of people had been using shovels to dig for the dozens still missing and lugging supplies to the disaster site by foot.

Landslides are a persistent problem in Indonesia. Last year they killed hundreds of people in a central Javan village and since then scores have died in similar incidents elsewhere in the country.

A nearby cyclone has worsened weather conditions on Flores, which lies 1,700 kilometers from Indonesia's capital, Jakarta.

Authorities have said there is an urgent need for food, tents, raincoats, mosquito nets, portable power generators and lamps in the disaster zone.

Relief efforts are focused on two villages, Gapong and Goreng Meni, where the bulk of those missing are buried.

The landslides destroyed many rice fields, which could lead to local food shortages, and knocked out telephone lines. Search and rescue teams are relying on citizen band radio to communicate with each other.

Heavy rain in Flores on Thursday last week forced 11,000 people in an area known as Reok to leave their homes as floods and landslides struck.

The Indonesian monsoon season is at its height, with heavy rains causing landslides and flooding in various parts of the archipelago.