According to Xinhua news agency, the center received a distress call at about 3:40 pm from a dry cargo carrier, alerting that the ship's cargo hold was flooded because of strong waves about two nautical miles north of Cezi island in the city of Zhoushan.
The ship was loaded with 4,700 tonnes of cement en route from Wuhu to Xiamen.
Four crew members have been saved.
Local authorities have dispatched more than 20 vessels to search for the missing members.
Before this incident, on December 22, a strong storm near Vietnam placed two Chinese-owned ships in distress. Namely, the Marshall Island flagged chemical carrier Chem Sinyoo reportedly blacked out on December 21 during the storm about 100 nautical miles Vietnam. The ship was heading to Shanghai. The crew attempted to repair the ship, but their task was very difficult as their ship was hit by several large waves.
As a result, the captain requested medical assistance from the Vietnamese authorities, reporting that one mechanic in the engine room, had lost his life, while four other crew members were badly injured.
The vessel did not have medical facilities aboard and required medical assistance. The Vietnamese Coast Guard sent two ships with medical staff to assist, and the four injured crew members were moved to a hospital.
In addition, relevant authorities also lost contact with a 3000 DWT general cargo ship, the Don Yang. The ship issued a distress call in a position about 190 nautical miles off southwest Vietnam.
According to Vietnamese authorities, because of high seas in the area, they were having difficulty reaching the vessel in distress. Chinese authorities also issued a call for assistance and one of the South China Sea rescue boats was trying to reach the area.
Later reports indicated that a passing containership located the crew after they abandon their sinking ship. The ship brought them safely aboard, in good condition.