PERTH, Australia — China’s official Xinhua News Agency reported that a Chinese ship that is part of the search effort detected a “pulse” signal Saturday in southern Indian Ocean waters. The report said it was not yet determined whether the signal was related to the missing jet.

Xinhua said a black box detector deployed by the ship, Haixun 01, picked up a signal at 37.5 kilohertz (cycles per second), the same frequency emitted by flight data recorders.

The Australian government agency coordinating the search would not immediately comment on the report.

Malaysia vowed Saturday that it would not give up trying to find the missing jetliner and announced details of a multinational investigation team to try to solve the aviation mystery, as the search for the plane entered its fifth week.

Military and civilian planes, ships with deep-sea searching equipment and a British nuclear submarine scoured a remote patch of the southern Indian Ocean off Australia’s west coast, in an increasingly urgent hunt for debris and the black box recorders that hold vital information about Malaysia Airlines Flight 370’s last hours.

After weeks of fruitless looking, officials face the daunting prospect that sound-emitting beacons in the flight and voice recorders will soon fall silent as their batteries die after sounding electronic “pings” for a month.

The Boeing 777 disappeared March 8 while en route from Kuala Lumpur, Malaysia, to Beijing with 239 people aboard. So far, no trace of the jet has been found.