(Updates with helicopters, ships deployed) JAKARTA, Dec 25 (Reuters) - Floods and landslides in Indonesia's Aceh and North Sumatra provinces have killed at least 80 people and forced tens of thousands to flee to higher ground, authorities in the region said on Monday. Aceh, still feeling the devastating effects of the 2004 tsunami, was hardest hit. Ridwan Sulaiman, head of social affairs in the province, said the death toll was now 42, although the figure could go higher as rescuers reach more remote villages. Authorities said an estimated 42,000 residents had been driven from their homes by the floodwaters. Most of the damage was in Aceh's Tamiang district, on the northern tip of Sumatra island. Floods killed 17 people, with almost 50,000 made homeless, in neighbouring North Sumatra province, officials said. Landslides triggered by the rains killed another 21 in the province's Muarasipongi district, Hashim Nasution, deputy mayor of Mandailing Natal, North Sumatra, told Elshinta radio. Nasution said local residents had just returned to their homes after fleeing last week's earthquake. "We are still trying to locate more people. We received a report that at least four people are still missing in the area," he said. Mustafa Abu Bakar, Aceh's acting governor, later told a press conference that army helicopters and navy ships had been deployed to deliver aid and help in the rescue efforts in the remote areas. He said about 5,000 people were still trapped in the Pinding district, with access roads cut off by the floods. Communications to the area were also down. Authorities have blamed heavy rains as well as the effects of deforestation for the destruction. Lack of adequate forest cover leaves the ground less able to absorb excess water. Sulaiman said some of the waters in Aceh had begun to recede, leaving behind thick mud that complicated rescue and aid efforts. The Bener Meriah regency was cut off and authorities were awaiting a helicopter to survey the damage, he said. He said the government and aid organisations had sufficient supplies of food, tents and medicine but transport capable of reaching remote areas remained a problem. Almost exactly two years ago, on Dec. 26, 2004, Aceh was hit by the Indian Ocean tsunami, which left some 170,000 dead or missing in the province.
