BEIJING - The powerful Typhoon Muifa will start to move over the East China Sea on Friday evening, according to a statement from China's National Marine Environmental Forecasting Center.

The typhoon was located about 820 km southeast of Ningbo City of east China's Zhejiang Province at 5 am Friday. It will approach the coastal areas of northern part of Zhejiang and southern part of Jiangsu Province on Saturday, the statement said.

The forecasting center is continuing its orange alert for sea waves, the second-highest alert in the four-level high wave warning system, warning that from Friday noon to Saturday noon, the East China Sea will see waves of 9 to 12 meters high and waters off Shanghai and Zhejiang will see waves of 3 to 4.5 meters high.

Waters off Jiangsu and Fujian Province will also see waves of 2.5 to 3.5 meters high, the statement said.

The center on Friday morning also issued a yellow alert, second lowest alert, for storm surges caused by the typhoon.

From Friday morning to Saturday morning, coastal areas along the Yangtze River's mouth to Fujian will see their water levels increase by 50 to 120 cm.

On early Saturday, some areas in Fujian will see their water levels slightly above the warning level, according to the statement.