Japan, Taiwan and China were all bracing for the storm, with Japan's meteorological agency warning of strong winds and heavy rain, as well as the risk of tornados, just two weeks after Typhoon Usagi wreaked havoc in the region.
At 1:00 pm (0400 GMT), Fitow was about 200 kilometres (125 miles) south-southwest of Naha, the capital of Okinawa, and moving slowly northwest, the agency said.
Japan Airlines, All Nippon Airways and its low-cost carrier Peach Aviation said that their flights to and from Naha had been cancelled because the typhoon.
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Hong Kong's Dragonair also said its Okinawa flights had been cancelled.
About 200 households lost electricity due to the storm, the Okinawa Electric Power said, adding that strong winds and heavy rain were hampering efforts to restore power.
The typhoon, named after a flower from Micronesia, was heading towards Taiwan, which said the storm would likely pass to the north of the island on Sunday.
The Central Weather Bureau in Taiwan said the typhoon had gathered momentum and was packing gusts of 137 kilometres per hour.
"Fitow is maintaining its strength and will bring heavy rains to northern and northeastern Taiwan, especially Taipei and New Taipei cities. Its impact is expected to be at the strongest on Sunday morning," the bureau said.
China has also issued a warning over the typhoon, which is set to hit the country's southeast coastline late Sunday.
The National Meteorological Centre gave an orange warning -- the second-highest in a four-tier system -- saying the storm would make landfall in the provinces of Zhejiang and Fujian, state news agency Xinhua reported.
Typhoon Usagi left 25 dead last month when it crashed into southern China, throwing the region's transport systems into chaos and leaving tens of thousands of airline passengers stranded in Hong Kong.
In 2007, a strong typhoon also called Fitow slammed into the Tokyo region, bringing territorial downpours and violent winds that left one person dead, more than 40 injured and flooded hundreds of homes.
