Super Typhoon Fung-wong, the most powerful storm to threaten the Philippines this year, has begun battering its northeastern coast, killing at least one person so far, disrupting power and forcing nearly one million people to evacuate as authorities urgently call for residents in high-risk areas to seek immediate shelter.

With an enormous 1,600km (994-mile) rain and wind band capable of affecting two-thirds of the archipelago, Fung-wong is striking as the country still is struggling to recover from Typhoon Kalmaegi, which killed at least 224 people in central provinces on Tuesday before moving on to Vietnam, where it killed five more people.

Fung-wong could make landfall on the main island of Luzon as early as Sunday night. More than 916,860 residents have fled vulnerable areas in northeastern provinces, including the Bicol region, which faces dual threats from cyclones and potential mudflows from the Mayon volcano.

During a televised address on Saturday, Defence Secretary Gilberto Teodoro Jr, who coordinates disaster response, warned of Fung-wong’s potentially catastrophic impact. The storm threatens vast regions, including the already devastated Cebu province and metropolitan Manila, the nation’s capital and financial hub.

The storm, the 21st to hit the Philippines this year, has sustained winds of 185km/h (115mph) and gusts as high as 230km/h (140mph).

According to the Office of Civil Defence, more than 30 million people could be exposed to Fung-wong’s hazards. While the Philippines hasn’t requested international aid after Kalmaegi, Teodoro indicated that the United States and Japan may provide assistance.

As Fung-wong approached, several eastern communities experienced power outages, reported Bernardo Rafaelito Alejandro, deputy administrator of the Office of Civil Defence.

Northern provinces in the storm’s projected path have closed schools and most government offices for Monday and Tuesday. Transportation disruptions included 325 cancelled domestic flights, 61 international flight cancellations and more than 6,600 people stranded at 109 seaports where maritime travel has been suspended.