Usagi, the strongest typhoon to land on the Chinese mainland this year, hammered south China's Pearl River Delta region in Guangdong province between Sunday afternoon and Monday morning.

Usagi was located 660 km southeast of Hong Kong at 5 pm Saturday, packing a wind speed of 187 km per hour at its center, and it was moving northwest at a speed of up to 20 km per hour, the National Meteorological Center said in its latest update.

The center issued the highest level of alert for Usagi, warning that it would bring gales and downpours to southern and southeastern coastal areas.

Though the typhoon did not hit Guangdong's neighboring Fujian province head-on, its cloud system has affected coastal areas in the province since Friday.

Giant waves could be seen along the beaches in Fujian's Pingtan county and heavy precipitation came with gales.

Fujian evacuated more than 80,000 people and deployed over 50,000 disaster-relief personnel ahead of Usagi, according to the Xinhua News Agency.

Su Shulin, governor of the province, said that "Typhoon Usagi is strong and dangerous", and that it posed a significant threat to Fujian. He asked officials to make adequate preparations.

Most shipping lines from Xiamen City to Kinmen and all lines from Quanzhou city to Kinmen were canceled on Saturday.