The Australian Maritime Safety Authority said all planes that headed for the search area in the southern Indian Ocean earlier Thursday were now returning to Perth. Ships, too, were leaving the area about 2,500 kilometers (1,550 miles) southwest of Perth that was buffeted by heavy rains and strong winds that brought low clouds and reduced visibility.
Eleven planes and five ships had planned to scour the sea for objects from Flight 370, which vanished early March 8 en route from Kuala Lumpur to Beijing with 239 people aboard.
Search planes have been flying out of Perth for a week, looking without any success for objects spotted in vague satellite images, the latest of which showed 122 objects floating in the ocean.
Finding them would give physical confirmation that the flight had crashed, and allow searchers to narrow the hunt for the wreckage of the plane and its black boxes, which could solve the mystery of why the plane was so far off-course.
Malaysian officials said earlier this week that satellite data confirmed the plane crashed while on a course toward the southern Indian Ocean. Malaysia Airlines on Thursday ran a full-page condolence advertisement with a black background in a major newspaper.
"Our sincerest condolences go out to the loved ones of the 239 passengers, friends and colleagues. Words alone cannot express our enormous sorrow and pain," read the advertisement in the New Straits Times.
The 122 objects captured by a French satellite ranged in size from 1 meter (3 feet) to 23 meters (75 feet). The sighting was called "the most credible lead that we have" by a top Malaysian official on Wednesday, but the search will now have to wait until the weather improves, echoing the frustration of earlier sweeps that failed to zero in on three objects spotted by satellites in recent days.
With the search in motion, Malaysian officials again sought to assuage the angry relatives of the flight's 153 Chinese passengers. But Defense Minister Hishammuddin Hussein also expressed exasperation, pointedly saying Chinese families "must also understand that we in Malaysia also lost our loved ones," as did "so many other nations."
The latest satellite images, captured Sunday and relayed by French-based Airbus Defense and Space, are the first to suggest a debris field from the plane, rather than just isolated objects. The items were spotted in roughly the same area as other objects previously seen by Australian and Chinese satellites.
At a news conference in Kuala Lumpur, Hishammuddin said some of them "appeared to be bright, possibly indicating solid materials."
But experts cautioned that the area's frequent high seas and bad weather and its distance from land complicated an already-trying search.
Malaysia said Monday that an analysis of the final known satellite signals from the plane showed that it had gone down in the sea, with no survivors.
Though officials believe they know roughly where the plane is, they don't know why it disappeared shortly after takeoff. Investigators have ruled out nothing—including mechanical or electrical failure, hijacking, sabotage, terrorism or issues related to the mental health of the pilots or someone else on board.
McDonald reported from Kuala Lumpur. Associated Press writers Eileen Ng in Kuala Lumpur, Christopher Bodeen and Didi Tang in Beijing, Kristen Gelineau in Sydney, Rod McGuirk in Canberra, Australia, Justin Pritchard in Los Angeles, Michael Tarm in Chicago, Eric Tucker in Washington and Nick Perry in Wellington, New Zealand, contributed to this report.