Australian authorities said Friday that the use of radar scanning in the search for the missing Malaysia Airlines passenger jet has been fruitless and that they would opt for a "visual" strategy in a bid to locate possible wreckage from the plane in the Indian Ocean.

"Noting that we got no radar detections yesterday, we have replanned the search to be visual," John Young, spokesman for the Australian Maritime Safety Authority, the agency leading the search for Flight 370 in the southern Indian Ocean, said in a video posted online.

Two search planes with "trained observers" looking out the windows are flying low and combing an area of the ocean off Australia's southwest coast where two objects that might be floating debris from the jet were seen Thursday on satellite images.

Another pair of planes are on the way to help in the search.

Australian Deputy Prime Minister Warren Truss said the objects seen in the images may already have sunk.

The Norwegian merchant vessel St. Petersburg arrived Thursday night in the area and two other ships, including an Australian warship, are making their way there to assist in the search effort.

The Malaysia Airlines jet, a Boeing 777-200 with 239 people on board, disappeared from radar screens some 40 minutes after it took off on March 8 from Kuala Lumpur on a red-eye flight bound for Beijing.

Malaysian Prime Minister Najib Razak told a news conference Saturday that the search for the jet would be reoriented from the South China Sea to the west, saying the plane was steered off course after someone on board deliberately disabled its transponder.

The aircraft - carrying 227 passengers, most of them Chinese, and a crew of 12 Malaysians - had enough fuel to fly for seven and a half hours. EFE