Thousands of fishing boats return to harbor to avoid potential damages from Typhoon Tapah in Lianyungang City, east China's Jiangsu Province. (File Photo: IC)

BEIJING, Sept. 30 (Xinhua) -- China's national observatory issued a yellow alert for Typhoon Mitag Monday, as it is expected to bring gales and torrential rains to eastern China.

The typhoon, the 18th of the year, is expected to make landfall at or pass by the north of Taiwan on Monday evening, and move northward to make another landfall at or pass by the central or northern coastal areas of Zhejiang Province Tuesday afternoon or evening, the National Meteorological Center said.

The center warned of strong winds and rainstorms in Taiwan and provinces of Zhejiang and Fujian.

It suggested people in affected areas avoid outdoor activities, and local authorities take precautions against possible flash floods caused by the downpours.

China has a four-tier, color-coded weather warning system for typhoons with red representing the most severe, followed by orange, yellow and blue.