Beijing (CNN) -- Seventy-two people are missing after three Chinese fishing boats sank in the South China Sea amid stormy weather caused by a typhoon, state media reported.
Two of the vessels foundered Sunday afternoon as they battled gales about 330 kilometers from the Chinese island of Hainan, the state-run news agency Xinhua reported. The third one sank Monday morning, it said.
As of Tuesday morning, rescuers had retrieved 16 survivors, the state-run China News Service reported, citing the Hainan government. Rescue operations have been hampered by strong gales and rough seas.
A total of five fishing boats with 171 crew aboard had been caught in the storm, the Hainan Maritime Search and Rescue Center said, according to Xinhua. The two other vessels managed to survive the harsh conditions.
All three boats that sank were from the southern Chinese province of Guangdong.
President Xi Jinping urged local authorities to do their utmost to find the missing or stranded and minimize casualties," state media reported.
Xi also ordered the armed forces and central government departments to help in the rescue effort.
The storm, Typhoon Wutip, made landfall in central Vietnam late Monday. Authorities there relocated tens of thousands of people from areas at risk as the storm approached.
CNN's CY Xu in Beijing and Elizabeth Joseph in Hong Kong contributed to this report.