Authorities said the rescuers were wading through floodwaters when a wall beside them collapsed, sending them into the fast current.
Noru, the 11th tropical cyclone to hit the Philippines this year, is expected to bring heavy to torrential rains over the capital region and nearby provinces on Sunday afternoon.
More than 60 people have been injured, including those who fell down in the rain or were hit by shards of glass, according to Japanese media reports.
The warning is issued only when it forecasts conditions seen once in several decades.
No casualties or major damage has been reported in Shanghai, with the city restarting public transit.
Typhoon Hinnamnor, the strongest global storm of 2022, is expected to also affect neighbouring Taiwan, Japan and Korea.
Officials and residents of areas that bore the brunt of Typhoon Rai pleaded for food, water and shelter as thousands of military, police and coast guard personnel deployed to deliver aid to survivors.
Several local train services near Tokyo were temporarily suspended as some flights and ferries connecting the city’s Haneda airport and outer islands have been cancelled.
Historic floods have claimed at least 51 lives in central China this week, including 12 people trapped in a subway during rush hour.
Storm Vamco causes severe floods and landslides in the central region of Vietnam after leaving 67 people dead and nearly 26,000 houses damaged in the Philippines.
Vietnam is prone to destructive storms and flooding due to its long coastline. Vamco will be the 13th storm that affects the Southeast Asian country this year.
The third typhoon to hit the storm-battered Philippines in as many weeks caused major flooding in Manila, trapping some people on rooftops and claiming at least one life in another part of the country.
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