Typhoon Sinlaku, the 13th tropical storm so far this year, was approaching the eastern coast of Taiwan and may land or skim over northeastern regions of the island on Saturday or Sunday, Xinhua quoted China's weather authorities as saying today. The storm strengthened into a typhoon on Wednesday, and was spotted at about 390 kilometers southeast of Hengchun City, Taiwan, at 10 a.m. on Thursday, packing up winds of 180 km per hour at the center. It is moving in a northwesterly direction at five to 10 km an hour, getting closer to the northeast coast of Taiwan, said the National Meteorological Observatory. It could make landfall or briefly touch the island on Saturday afternoon or Sunday morning, and then continue to head towards the Chinese mainland's Fujian Province and Zhejiang Province, said the observatory. Heavy rains are forecast in Taiwan, northeastern regions of Fujian and eastern parts of Zhejiang over the next two days because of Typhoon Sinlaku, and there could be torrential rains in some regions of Taiwan. The storm was still strengthening and could develop into a super typhoon, meteorological experts said. The observatory also said the exact course and impact of the storm remained uncertain.