Yagi will be the strongest typhoon to strike the island province of Hainan in the past decade, China's meteorological body said on Wednesday.

Yagi has paralyzed normal operations in the coastal cities of Guangdong and Hainan provinces, it added.

The typhoon, the 11th of this year, grew into a super typhoon on Wednesday, and is estimated to make landfall between Qionghai, Hainan, and Dianbai, Guangdong, on Friday afternoon or later in the evening, said Xiang Chunyi, a forecaster of the National Meteorological Center.

Xiang attributed the formation of the super typhoon to a strong tropical storm.

The typhoon is expected to cause torrential rainfall and gusting winds in cities along the coast of Guangdong from Thursday to Saturday, said Liang Qiaoqian, chief forecaster at the Guangdong provincial meteorological service.

The two provinces upgraded their anti-typhoon emergency response to their top levels on Thursday morning.

In Zhanjiang, Guangdong, which is forecast to be hit hard by the typhoon, vehicles — except for emergency rescue and the kind — have been told to stop operating, while residents have been urged to reduce outdoor activities. Power supply for major outdoor projects has also been cut beginning Thursday, local authorities said.

In Hainan, 34,707 fishing boats have been secured in harbors or designated safe areas, and 78,261 individuals working off the coast have been relocated to land, the local government said.

Wenchang, Hainan, another city at high risk, has charted plans to relocate around 240,000 residents to safe areas.

Meanwhile, coastal tourist attractions and beaches in Guangdong and Hainan have been told to close temporarily, and ferry services across the Qiongzhou Strait have also been suspended from midnight Wednesday until Sunday.

In Zhuhai, Guangdong, about 40 flights were canceled on Thursday to ensure safety. Similar measures were adopted in Hainan.

Trains were affected as well. As of 6 pm on Thursday, all trains on the high-speed railway loop in Hainan and Haikou urban rail lines were suspended, with expected further suspensions through Friday and Saturday.

The marine department of the Hong Kong-Zhuhai-Macao Bridge will be closed temporarily starting at 9 pm on Thursday. It has already introduced traffic controls for inland river vessels, banning riverboats from operating under the bridge to avoid any accident on Thursday, according to the bridge authority.