The number of casualties of flash floods and landslides hitting North Sulawesi province in eastern Indonesia rose to 18 on Friday, with two people remaining missing, a government spokesman said. Torrential rains over the past few days had bloated at least four rivers in the province from Wednesday to Thursday and swelled their banks, submerging the area, sweeping away cars and over 100 houses, said Sutopo Purwo Nugroho, spokesman of the national disaster management and mitigation agency. "The number of the toll scaled up to 18 today (Friday)," he told Xinhua via the phone. Not all of the corpses had been found, he added. The floods not only damaged houses and carried away vehicles, but also collapsed four bridges, isolating thousands of people in hamlets, Sutopo said. Landslides also buried many houses, he said. As the water receded, most of the more than 40,000 people displaced have returned to clean out their houses, Sutopo said, adding that the delivery of emergency relief aids is underway. An Air Force Hercules plane had airlifted logistics and equipment from Jakarta to the areas hit by the disasters since Friday morning and another Hercules would do so on Saturday, he said. The total relief aids to be sent by air are set at 57.2 tons. Seasonal downpours cause incurred floods every year in Indonesia, a chain of 17,500 islands where millions of people live in vulnerable plains near rivers. Environmentalists have blamed illegal logging and deforestation in the vast archipelago country for exacerbating flooding.