BEIJING - An alert was issued on Thursday for typhoon Usagi, which was upgraded to a super typhoon at 5 pm, according to China's meteorological authority.

At 7 p.m. Beijing time, the National Meteorological Center (NMC) issued a yellow alert for the typhoon, the third highest on the country's four-tier weather warning system -- with red being the most severe, followed by orange, yellow and blue.

The NMC said the center of Usagi, the 19th typhoon this year, was at about 850 km southeast of Taiwan at 5 pm and was moving northwestward at a speed of around 15 km per hour with strengthening force.

Affected by the super typhoon, strong wind will sweep waters in the east and north of Taiwan, the sea near China's Diaoyu Islands, the south of East China Sea and the northeast of South China sea, the center said.

The NMC said Usagi is gradually approaching China's southeastern coastal regions and may hit coasts near Guangdong Province between Sunday and Monday.

The authority urged related government organs to take precautions against the typhoon.