This is the shocking moment floods smashed through hotel doors during Typhoon Ragasa's onslaught in Hong Kong.

Dramatic footage shows murky water crashing against the closed glass swing doors of the Fullerton Ocean Park Hotel in the Aberdeen district, shattering the panels and surging into the lobby.

The powerful seawater rush swept violently through the building as hotel staff and guests clung to the walls for safety on September 23.

Another surge forced a man in black, who had been holding onto a panda-themed cardboard display, off his feet before a fellow guest rushed to help him stand as fresh waves poured inside.

Local media reported that massive waves breached the hotel's sandbags and protective barriers.

The Fullerton Ocean Park Hotel later issued a statement saying the safety of guests and staff remained their top priority.

The management said additional personnel had been deployed to manage the impact of the storm and ensure guests could remain safely and comfortably inside.

The hotel in the former British outpost confirmed that no injuries were reported.

The Hong Kong Observatory warned of 'phenomenal' ocean swells as storm surges were predicted to reach up to four metres (13 feet) in some areas.

Super Typhoon Ragasa, said to be the strongest storm of the year so far, is roaring towards Hong Kong after tearing through the northern tip of the Philippines, killing at least one and displacing thousands.

It made landfall in the country's remote and poverty-stricken Babuyan Islands at 3 pm local time on Monday. It arrived as the Philippines continues to grapple with weeks of severe flooding brought on by an unusually intense monsoon season.

Hong Kong authorities have grounded at least 700 flights from Tuesday evening as Ragasa barrels toward the Chinese coast. Panicked locals have also cleared grocery shelves as they prepared to hunker down in their homes.

China has ordered schools and businesses shut in at least 10 cities as citizens brace for Ragasa's landfall in the coastal province of Guangdong.