China's marine forecast station on Sunday issued a yellow alert for a powerful typhoon moving into the East China Sea after barrelling into southwestern Japan.
Typhoon Phanfone, which was downgraded from an earlier super typhoon, is moving at 20 km per hour, according to the station.
The typhoon could create waves up to seven meters high in the eastern part of the East China Sea between Sunday noon and Monday noon, according to the forecast.
Waves as high as 3 meters will be seen off the coast near Shanghai and Zhejiang Province, the center said, warning vessels operating in the waters to take precautions.
China has a four-tier color-coded weather warning system, with red representing the most severe warning, followed by orange, yellow and blue.
The station said another typhoon, Vongfong, which was about 660 kilometers east-southeast of Guam as of Sunday morning, is approaching the Mariana Islands.