SEOUL - Typhoon Bolaven swept across South Korea Tuesday, leaving tens of thousands of households nationwide without power and causing property damage as it made its way northward.

A wave is seen in Busan, about 420 km southeast of Seoul Aug 28, 2012. South Korea was hammered by Typhoon Bolaven, likely to be the most powerful storm in a decade in the country, on Tuesday morning. [Photo/Agencies]

The most powerful typhoon to hit the Korean Peninsula in a decade, Bolaven sank two Chinese fishing boats in waters off the country's southernmost island of Jeju early Tuesday morning, leaving 12 out of 34 unaccounted for.

The storm, with winds gusting at up to 40 meter per second, uprooted trees, broke signposts and damaged buildings, leading to flight and ferry cancellations and a ban on access to local beaches and mountains.

Some 200,000 households are without power while 54 people have been displaced as of 11 am, according to the National Emergency Management Agency.

The typhoon is projected to reach Seoul, the South Korean capital with a population of 10 million, at around 3 pm. A preliminary typhoon alert was upgraded at 9 am to a warning in Seoul. All elementary and secondary schools in the metropolitan area are closed for the day.

A man stands near part of a prefabricated house which has broken off during Typhoon Bolaven in Mokpo, about 410 km southwest of Seoul Aug 28, 2012. [Photo/Agencies]