BEIJING - China issued the highest typhoon warning on Thursday as Typhoon Saola, packing winds of more than 200 kph (125 mph), headed towards the southeastern coastline, threatening Hong Kong and other major manufacturing hubs in nearby Guangdong province.

Chinese forecasters issued a typhoon red warning at 6 a.m. (2200 GMT). China's National Meteorological Center said Saola, currently located about 315km (183 miles) southeast of Guangdong province, will move northwest across the South China Sea at a speed of about 10 kph (6 mph), gradually approaching the coast of Guangdong, then slowly weaken in intensity.

Wind speeds at noon (0400 GMT) were clocked at 209 kph (130 mph).

Saola will make landfall along the coast somewhere from Huilai County in Guangdong to Hong Kong on the afternoon to the night of Sept. 1, the center said, adding with its forecasted intensity, it could be among the five strongest typhoons to land in Guangdong since 1949.

As Saola approaches, Guangdong's Shenzhen city said it would upgrade typhoon warning level to yellow - the second lowest - at 6 p.m. on Thursday, and suspend classes at nurseries, kindergartens, primary and secondary schools.

China Southern Power Grid said it is stepping up inspection of equipment and strengthening measures to prevent water leakage in basement power rooms.

China Railway has suspended several major train lines and Shanghai halted trains heading to Guangdong, according to local media.

The Hong Kong Observatory said it will raise its strong wind Signal to No. 3 - the second lowest - later Thursday.

Saola will also bring storm surges to coastal low-lying areas, the observatory noted, estimating Saola is currently about 440km (270 miles) from the metropolis.

Until 8 a.m. (0000 GMT) Friday there will be heavy rainfall in parts of Fujian and areas of Guangdong. Downpours could be 100-220mm (3.9 inches to 8.7 inches) in some areas.

Saola's winds are also affecting Fujian province, where videos on social media showed waves crashing along the coastline. The meteorological administration of Shishi city issued a typhoon blue warning.