More than 76 people have been killed, while dozens of others are still missing, after floods and landslides hit Indonesia and neighboring East Timor.

Floods caused by torrential rains wreaked havoc on the island of Flores as far as East Timor, east of the Indonesian archipelago.

Indonesia's disaster management agency said 55 people were killed and 40 others missing in the multi-island province of East Nusa Tenggara, after Cyclone Ciruga triggered floods, landslides and strong winds amid torrential rains since the weekend.

It added that more than 400 people were evacuated and thousands were affected by the bad weather.

Several bridges collapsed, trees fell, some roads blocked and at least one ship sank, the government agency said, with the typhoon also causing high waves, complicating search and rescue operations.

While local officials confirmed the death toll had risen to more than 100, the disaster management agency said it could not confirm that.

The Indonesia Meteorological Agency said Cyclone Ciruga slammed into the Savoy Sea, southwest of Timor Island, in the early hours of Monday morning, warning that it could bring more rain, waves and winds.

The floods caused widespread destruction and forced thousands to leave their homes (Reuters)

Reuters quoted an official in East Timor as saying that at least 20 people were killed by a tropical cyclone that swept the Southeast Asian country.

"According to preliminary data, the total loss of life is 21," Ismael da Costa Papo, director of civil protection, told reporters.

He added that more than 1,500 people were evacuated to shelters in the capital, Dili.

Indonesia often witnesses deaths from landslides and floods in the rainy season, and environmental advocates stress that deforestation has exacerbated these disasters.

In January, floods in the Indonesian town of Sumedang in West Java killed 40 people.

Last September, at least 11 people died in landslides in Borneo, months after dozens were killed in a similar disaster in Sulawesi.

The National Disaster Management Agency estimates that 125 million Indonesians, half of the country's population, live in areas at risk of landslides.