Seoul, South Korea (CNN) -- Four Chinese fishermen died and 12 were missing in stormy waters off South Korea's Jeju Island on Tuesday as Typhoon Bolaven plowed toward the Korean Peninsula after making landfall on Okinawa.
Maritime police on Jeju Island said 17 people had been rescued but searches were on for those still unaccounted for after two boats capsized early Tuesday as Bolaven raged.
Okinawa, meanwhile, emerged relatively unscathed after the typhoon buffeted it with maximum sustained winds near its center of 185 kilometers per hour (115 mph), according to the Hong Kong Observatory, which monitors storms in the region.
That wind strength put Bolaven in the "super typhoon" category. And with a cloud field of 2,000 kilometers (1,250 miles), it was 20 times larger than Okinawa's length. The storm has since weakened somewhat to become a "severe typhoon."
Okinawa, which is situated in an area of the western Pacific Ocean where typhoons are frequent, avoided the kind of destruction that some other storms have caused in East Asia this summer.
Five people were injured on the island, the local authorities said, and 549 residents took shelter in public buildings to avoid potential damage to their homes. About 17,500 households lost electricity as the storm damaged power lines.
Storm chaser James Reynolds was on the northwestern coast of the island during the worst of the typhoon.
"Like the rest of the population we all just kind of holed up in the strong and sturdy buildings which make up Okinawa," he said Monday.
The infrastructure on Okinawa is designed to withstand violent storms. "Everything's made of solid concrete," Reynolds said.
The damage was also limited because Bolaven didn't bring winds as powerful as initially feared, said Morichiyo Ohshiro, an official from the Okinawa Prefecture Disaster Prevention and Crisis Management Division.
North of Okinawa, the Amami Islands suffered a major power outage as a result of the typhoon. According to Kyushu Electric Power Corporation, which provides power to the area, 56,300 households were without power as of Monday morning.
All residents of about 2,540 households on Yoron, one of the islands in the chain, were advised by the local authorities to relocate to nearby public facilities as the storm made its way northward.
President Lee Myung-bak of South Korea on Monday called on government agencies to take measures to minimize damage from the approaching storm, the national news agency Yonhap reported, citing Park Jeong-ha, a spokesman for Lee.
Typhoon Tembin made landfall in southern Taiwan a few days ago, and was expected to work its way toward Hong Kong. But Bolaven, which is much stronger, has stopped Tembin's movement toward Hong Kong and has been spinning it around.
"As Typhoon Bolaven moves northward towards the Yellow Sea, it will drag Tembin toward the China coast very near Shanghai," said CNN International meteorologist Tom Sater. "That's an amazing change in direction."
CNN's Paula Hancocks, Yoko Wakatsuki and Ralitsa Vassileva; and CNN meteorologist Pedram Javaheri contributed to this report.