Beijing - Rescuers cut through the bottom of an upended tugboat Friday to free a Chinese interpreter and searched for 22 more missing people, including eight foreigners, after the vessel capsized in the Yangtze River, the state-run Xinhua News Agency and officials said.Four Singaporeans, an Indonesian, a Malaysian, an Indian and a Japanese were among the missing following the overturning of the tugboat Thursday afternoon during a test voyage in the river's Fubei Channel in the eastern province of Jiangsu, Xinhua said.Three people have been rescued, including the interpreter early on Friday, some 14 hours after boat toppled over with 25 people aboard, the report said.Rescuers said they believed people were trapped in boat's cabin and were using a crane to try to lift the sunken boat, but that swift currents were making that difficult, Xinhua said. The missing included the boat's owner and engineers, it said.Wang Zhenkai told Xinhua he was the interpreter for a Japanese engineer who was pulled away by swirling currents as the boat went down. Wang said he survived by holding onto a hydraulic pump."Only the two of us were in the cockpit. We had just finished the host load test of the boat's main engine when the vessel suddenly slid over. Water immediately filled in," Wang was quoted as saying.The Jiangsu provincial government's news office said that 27 vessels were involved in the search and rescue operation, but had no further details about the sinking.