Typhoon Haiyan is battering the central Philippines with sustained winds of 314 km/h (195mph).
Meteorologists say that if initial estimates based on satellite images are borne out, it could be the most powerful storm ever to make landfall.
The storm has forced millions to seek shelter in 20 provinces and at least three people have died, officials say.
The region was already struggling to recover from a powerful earthquake last month.
The authorities have warned that more than 12 million people are at risk from the category-five storm, including in Cebu, the country’s second largest city with a population of 2.5 million.
Two people were electrocuted in storm-related incidents and another was killed after being struck by lightning, according to officials. Seven others were reported injured.
Reports say power and communications have been almost completely lost in the island provinces of Samar, Leyte and Bohol.
The storm – known locally as Yolanda – was not expected to directly hit the capital Manila, more than 600km (370 miles) to the north.