(CNN) -- At least 20 people have died after Typhoon Usagi slammed into southern China, state-run broadcaster CCTV reported Monday.
Usagi has forced the evacuation of tens of thousands of people, the cancellation of hundreds of flights and the closing of a major shipping lane, according to state media.
At one point the most powerful storm so far this year, Usagi has menaced the region for days as a super typhoon, leaving at least two people dead and a dozen injured in the Philippines and Taiwan before making landfall in the Chinese province of Guangdong, northeast of Hong Kong.
In preparation for the storm's arrival, four of six reactors at the Daya Bay Nuclear Power Station in Shenzhen reduced their operating capacity, Guangdong authorities told the state-run Xinhua news agency.
Tens of thousands of people were evacuated from along the coast in Guangdong province as forecasters warned that heavy rains along with a storm surge would cause flooding, Xinhua reported, citing government officials.
In neighboring Fujian Province, more than 80,000 people were evacuated and 50,000 disaster-relief personnel were deployed, Xinhua reported.
The storm also wreaked havoc on transportation, forcing the cancellation of more than 300 flights at Hong Kong International Airport, according to airport officials.
Major Chinese airlines, including China Southern Air, canceled flights into the provinces of Guangdong and Fujian as well as Hong Kong and Macau, Xinhua reported.
A major shipping lane between Guangdong province, Hong Kong and Taiwan was closed Saturday in anticipation of the storm's arrival.
More than 22,000 fishing boats in Fujian and another 20,000 in Guangdong have been ordered into port, Zhang Dong, chief weather forecaster of Guangdong provincial meteorological center, told Xinhua.
East Asia is buffeted for several months a year by heavy storms that roll in from the Pacific. Usagi has eclipsed Super Typhoon Utor, which hit the Philippines and South China last month, as the strongest storm of the year so far.
About 50 people died as result of Utor in China, and 11 people were killed in the Philippines.