Sub still searching for missing plane; to be done in week

PERTH, Australia (AP) - An underwater robotic submarine is making its seventh dive into the depths of the Indian Ocean, searching for a missing Malaysian airliner.

As the hunt for Flight 370 hit week six Saturday, the search coordination center says the Bluefin 21 unmanned sub is expected to finish its current search within the next week, after completing six missions and so far coming up empty.

Its search area forms a 10-kilometer (6.2-mile) circle around an underwater signal detected April 8 that was believed to be coming from the aircraft's black boxes before their batteries died.

The sonar scan of the seafloor in that area is expected to be completed in five to seven days.