Beijing's Fangshan district said it would deploy helicopters to drop off food, drinking water and emergency supplies to villages in mountainous areas that have been cut off.

In nearby Tianjin, where rain has become intermittent, 35,000 people have been evacuated from homes and the local government fortified river banks and stepped up the inspection and repairs of power, water and communications lines.

Food delivery giant Meituan also added staff and extended delivery times as orders for vegetables, meat and eggs rose 50 percent on its app and overall shopping increased 20 percent, media reported.

The death toll in Beijing rose to 11 on Tuesday with 13 people still missing, while in neighboring Hebei province, nine people died and six were missing.

President Xi Jinping demanded thorough search and rescue efforts for those missing or trapped, instructing authorities to minimize casualties and restore living conditions to normal as soon as possible, state media reported.

The finance ministry also announced it would allocate 110 million yuan (US$15 million) for rescue work in the Beijing-Tianjin-Hebei region.

Doksuri, one of the strongest storms to hit China in years, weakened as it rolled inland and dumped non-stop precipitation in northern cities over a few days. Authorities have warned risks of further floods and other geological disasters remained.

Localized thunderstorms and strong winds were forecast on Tuesday for Beijing, Tianjin and Hebei, state broadcaster CCTV said, as rainfall stretched into a fourth day.

Rivers have swollen to dangerous levels, prompting Beijing to use a flood storage reservoir for the first time since it was built 25 years ago. As of Monday night, China's capital city had sealed off over 100 mountain roads and evacuated more than 52,000 people from their homes.

Several subway lines in the capital, including trains in western suburbs, were suspended on Tuesday. Beijing's Mentougou district in the west saw dramatic damage a day before, after torrential rains turned roads into rivers, sweeping cars away.

Nearly 400 flights were cancelled on Tuesday and hundreds delayed at Beijing's two airports, tracker app Flight Master showed.

Beijing recorded an average of 260 millimeters of rainfall from Saturday to early Monday, with the Changping Wangjiayuan Reservoir logging the largest reading at 738.3 mm.

The city government said rainfall over the past few days has broken records from a severe storm 11 years ago. In July 2012, Beijing was hit by what was then the strongest storm since the founding of modern China, with the city receiving 190.3mm of rain in one day, affecting more than 1.6 million people.

In Hebei, precipitation from Saturday to Monday at one local weather station totaled more than the amount normally seen over half a year, with rainfall amounting to 1,003 mm for the three-day period. Precipitation in the county where the station is located averages 605 mm a year.

Further west in Shanxi, a total of 42,211 people in the province had been relocated as of Monday.

Doksuri swept through coastal Fujian last week, taking a 14.76 billion yuan direct economic toll on the southeastern province and affecting almost 2.7 million people, with close to 562,000 evacuated from homes and more than 18,000 houses destroyed, state media reported.