TAIPEI, Taiwan (AP) — The most powerful typhoon of the year swept through the Luzon Strait separating the Philippines and Taiwan on Saturday, battering island communities with heavy rains and strong winds as it headed straight for Hong Kong. Typhoon Usagi weakened from a super typhoon — those with sustained winds of at least 241 kilometers (150 miles) per hour — and veered westward during the day, likely sparing southern Taiwan from the most destructive winds near its eye. At least two people were killed in the Philippines, and two others were missing. By Saturday evening, the storm had maximum sustained winds of 173 kph (108 mph) and gusts of up to 209 kph (131 mph), and was 150 kilometers (94 miles) southwest of Taiwan's southernmost point, the Central Weather Bureau said. But gusts exceeding 230 kph (144 mph) were recorded on the Taiwanese island of Lanyu, with dangerous winds buffeting the holiday resort of Kending on the Hengchun peninsula as the storm made its closest approach to the area. The Hong Kong Observatory said late Saturday night that Usagi was about 530 kilometers (329 miles) east-southeast of the city. It said the storm's maximum sustained winds would weaken to 165 kph (103 mph) as it approaches Hong Kong on Sunday afternoon before making landfall overnight. The observatory issued a No. 3 Standby Signal and warned that the storm posed a "severe threat" to the city. Cathay Pacific Airways and Dragonair said flights Saturday were unaffected except for one canceled flight, but both airlines said flights to and from Hong Kong International Airport would be canceled from 6 p.m. Sunday and resume Monday if conditions permit. China's National Meteorological Center announced a red alert, its highest level, as the storm maintained its track toward the manufacturing heartland of the Pearl River Delta. The observatory warned Usagi would impact coastal areas of Guangdong, Zhejiang and Fujian provinces. In Taiwan, more than 3,000 people were evacuated from flood-prone areas and mountainous regions as the government deployed military personnel into potential disaster zones. The storm system dumped up to 520 millimeters (20 inches) of rain along the eastern and southern coasts in a 20-hour period, with officials warning that more than 1,000 millimeters (39 inches) could drop before the storm leaves Sunday. Local officials closed mountain highways blocked by landslides and suspended train services connecting the east and west coasts as power outages and rising floodwaters affected thousands of homes. Rivers swollen with fast-moving water and debris thrown down from steep and unstable mountain catchment areas threatened bridges on both sides of the island. In the Philippines, a 50-year-old man and a 20-year-old woman drowned when a passenger boat capsized in rough waters off northeastern Aurora province, the Office of Civil Defense said Saturday. Two other people were missing, while the nine other passengers and crew were rescued from the boat, which capsized Friday. The typhoon blew out of the country late Saturday after triggering landslides and floods, uprooting trees, and damaging houses, roads and bridges in parts of the northern and central Philippines. Usagi has a massive diameter of 1,100 kilometers (680 miles), with its outer rain bands extending across Luzon, all of Taiwan and more than 100 kilometers (63 miles) into China's interior, satellite images showed.