CANBERRA,?Australia?-?The material that washed ashore in southwest Australia appears to not be from the missing Malaysian plane, officials said Thursday.

The Australian Transport Safety Bureau examined detailed photographs of the material, apparently sheet metal with rivets, and is satisfied it is not related to the plane, the search coordinator said.

The Malaysia Airlines flight from Kuala Lumpur to Beijing veered off course and disappeared March 8 in a still-baffling mystery and is believed to have crashed in the remote southern Indian Ocean. It had 239 passengers and crew.

The Joint Agency Coordination Centre also said Thursday a robotic submarine had scanned more than 90 percent of a 310-square-kilometer (120-square-mile) search area but has found nothing of interest. The sub is creating a three-dimensional sonar map of the ocean floor near where signals consistent with airplane black boxes were heard.

The next phase of the search is likely to be decided in a week and likely would involve using more powerful towed side-scan commercial sonar equipment, similar to what found the Titanic wreck in 1985.

The search center also said 11 ships and 11 planes were expected to search nearly 50,000 square kilometers of the ocean surface northwest of Perth on Thursday. Weather had hampered the visual search for the past two days.