Investigation of pings yet to bear fruit

Ships off Australia listening for underwater signals from the flight recorder, or black box, of Malaysia Airlines Flight MH370 have not been able to relocate signals, or "pings", that were first detected last weekend, authorities said.

Since the airliner vanished on March 8 with 239 people on board, including 154 Chinese passengers, time is running out to find the signals because the black box batteries are nearly drained, authorities said.

Transmissions picked up by Australia's Ocean Shield ship on Saturday and Sunday are consistent with those from aircraft black boxes. Authorities in charge of the search said they will continue to scour the remote southern Indian Ocean for a few more days before they consider sending down a mini-submersible to conduct investigations.