China's Xinhua News Agency says a Chinese ship searching for Malaysia Airlines Flight 370 has detected a 'pulse' signal.
The report says a black box detector deployed by the vessel picked up a signal at 37.5Hz per second.
The report said it was not determined whether the signal was related to the missing jet.
A black box detector deployed by the vessel, Haixun 01, picked up a signal at 37.5Hz per second at around 25 degrees south latitude and 101 degrees east longitude, Xinhua said.
The Australian government agency coordinating the search would not immediately comment on the report.