TOKYO, Sept. 23 (Xinhua) -- The Japan Meteorological Agency said on Monday that Typhoon Tapah, which left dozens of people injured in southern and southwestern Japan, had weakened to an extratropical cyclone in the Sea of Japan.

According to the Fire and Disaster Management Agency, the season's 17th typhoon, which traveled over the sea through Monday morning, has left more than 50 injured in the prefectures of Okinawa, Saga, Nagasaki and Miyazaki as it brought strong winds over the weekend.

Kyushu Electric Power Co. said blackouts continued to affect six of the seven prefectures on the island of Kyushu, with over 30,000 homes without power at one point. As of 5 p.m. local time on Monday, about 8,500 households are still without power.

The weather agency said it is likely to approach northern Japan between Monday night and early Tuesday morning. Weather officials are warning of strong winds, high waves, mudslides, flooding and swollen rivers, as well as lightning strikes and sudden wind gusts across wide areas.