South Korea remained on alert Sunday as a powerful typhoon, Haishen, has been marching northward amid a forecast that it will soon affect the peninsula directly, Yonhap reported. The 10th typhoon of the season is expected to reach waters between the southern island of Jeju and the Kyushu region of Japan on Monday morning, according to the Korea Meteorological Administration (KMA). It's then likely to head north over the East Sea, although it was initially expected to land on the peninsula. Haishen was travelling northward at a speed of 31 kilometers per hour in waters about 200 km south-southwest of Japan's Kagoshima prefecture as of 5 p.m. Sunday, KMA said. Heavy rains and strong winds are forecast across South Korea throughout Monday, it added. The state weather agency said the typhoon is likely to reach an area about 310 km east of Seogwipo City on Jeju at 3 a.m. on Monday and waters 80 km east-northeast of South Korea's southeastern port city of Busan at 9 a.m. on the same day. It is expected to reach waters about 90 km east of Gangneung in Gangwon Province at 3 p.m. on Monday and waters about 120 km south of Chongjin in North Korea at 9 p.m. on the same day. The Korea Forest Service (KFS) raised the landslide alert to "seriousness," the highest in the four-tier system, for Jeju, Busan, Ulsan and the provinces of South and North Gyeongsang, Gangwon and South Jeolla. It lifted the alert to "watch" for Seoul and 10 other major cities and provinces. Haishen would be the second typhoon to hit the nation in a week.