GUANGZHOU -- South China's Hainan and Guangdong provinces have been placed on high alert as Typhoon Wipha, the sixth typhoon of the year, is expected to make landfall along the coast Sunday afternoon or evening.

As of 7 am Sunday, Typhoon Wipha was observed at 21.7 degrees north latitude and 114.9 degrees east longitude, with the maximum wind speed near its center reaching 33 meters per second. It is expected to move westward at around 25 km per hour, with its intensity continuing to strengthen, according to meteorological forecasts.

In Guangdong's Zhuhai city, where strong winds and heavy rainfall are forecast, authorities raised the typhoon alert to red and upgraded the emergency response for typhoon control to Level I at 3 am Sunday, according to the local meteorological bureau.

The Hong Kong-Zhuhai-Macao Bridge was temporarily closed in response to the typhoon. Outbound customs clearance at Zhuhai Port of the bridge was suspended at 2:30 am, followed by the closure of the main bridge at 3:30 am, according to the bridge's management bureau.

School classes, transportation and business activities have been suspended across Zhuhai, and residents have been urged to stay indoors.

At 8:30 am Sunday, Hainan raised its emergency response for flood and typhoon control from Level IV to Level III, as strong winds and rainstorms are expected to impact the island province between Sunday and Tuesday, according to the provincial emergency management bureau.

In the provincial capital of Haikou, various departments are taking precautions ahead of the typhoon.

The maritime authority is carrying out electronic inspections in affected waters, maintaining real-time vessel monitoring and deploying personnel for on-site checks.

Water affairs departments have organized drainage teams to inspect and maintain facilities, opened manhole covers in advance to facilitate drainage, and set up warning signs.

The power department has stationed repair vehicles in key areas, while emergency plans have been activated for vegetable reserves to ensure market supply.

China's national observatory issued a yellow alert for Typhoon Wipha on Saturday.

China has a four-tier emergency response system, with Level I being the most severe response, and a four-tier color-coded weather warning system, with red representing the most severe, followed by orange, yellow and blue.