More than 20 people were missing Friday, including a Japanese engineer and several other foreigners, after a tugboat sank in the Yangtze River in eastern China, state media and local authorities said.
Three people had been rescued as of Friday morning.
The boat with 24 to 25 people onboard sank around 3 p.m. Thursday while it was undergoing a trial voyage in the river's Fubei Channel in Jiangsu Province, Xinhua News Agency said.
Indian, Japanese and Singaporean nationals are believed to be among seven or eight missing foreigners.
More than 20 vessels were deployed in the search, but Xinhua cited rescuers as saying their operations were being hampered by swift and cold currents.
The missing Japanese engineer is in his 60s, according to local authorities.
The Japanese Consulate in Shanghai has called on China to make every effort to rescue the passengers.
"The vessel suddenly slid over. Water immediately filled in," Xinhua quoted one of the three rescued people, Wang Chenkai, as saying.
Wang, who was working as an interpreter for the Japanese engineer, said the vessel went down when they finished testing its main engine and he tried to hold onto the Japanese engineer, but they were separated by the currents.
The tugboat was manufactured in October by Anhui Bengbu Shenzhou Machinery, which notified port authorities in advance about the trial voyage and its cruising route, according to Xinhua.