BEIJING/CANBERRA - Search activities for the missing Malaysian jet concluded Saturday with further sightings of potential debris but again no confirmation, Australian maritime rescue authorities said.

A Chinese Ilyushin IL-76 aircraft spotted three suspicious objects Saturday in a new search area north of the previous focus in the southern Indian Ocean.

The latest items are white, red and orange, respectively, according to a Xinhua reporter aboard the military plane.

A marker was dropped and the Chinese crew have informed Australian authorities of the new findings.

Five international aircraft spotted "multiple objects of various colors" in the new search area, some 1,850 km west of Perth, the Australian Maritime Safety Authority (AMSA) said Saturday.

Some looked like they were from fishing boats and nothing could be confirmed until they were recovered by ships, it added.

Saturday's search activities involved a total of eight aircraft and covered an area of about 252,000 square km, AMSA said.

They included three Royal Australian Air Force (RAAF) P3 Orions, a Japanese Coast Guard jet, a Japanese P3 Orion, a Royal New Zealand Air Force (RNZAF) P3 Orion, a Chinese People's Liberation Army Air Force Ilyushin IL-76, and one civilian jet acting as a communications relay.

Royal Australian Navy vessel HMAS Success, the Chinese Maritime Safety Administration ship Haixun 01, China Rescue and Salvage Bureau ship Nan Hai Jiu, and the Chinese Navy ship Jinggang Shan arrived in the search area Saturday and a further five ships should arrive Sunday.

The weather in the search area was described as reasonable; however, visibility was reduced to about 4 km due to showers.

The search would resume Sunday morning, AMSA said.

A device for locating the black box would be put onto an Australian navy ship to join the search, Australian Prime Minister Tony Abbott told media Saturday.

"It will be taken to the most prospective search area and if there is good reason to deploy it, it will be deployed," he told reporters in Sydney, adding it would be taken aboard the ship in Perth.

So far, no debris had been recovered in the adjusted search area, he said.

The search area was shifted about 1,100 km northeast Friday on what was said to be a credible new lead.

The new search area, about 319,000 square km, is about four times bigger than the previous search area in the southern Indian Ocean.

The prime minister also warned of the difficulty of the task.

"We should not underestimate the difficulty of this work," he said. "These are inhospitable seas. We are trying to find small bits of wreckage in a vast ocean."

MH370 mysteriously vanished on a flight from Kuala Lumpur to Beijing on March 8 carrying 239 people.

Officials believe someone on board the Boeing 777-200 may have shut off the plane's communications systems before flying it thousands of miles off course.

Malaysian Prime Minister Najib Razak said Monday that evidence showed the flight had "ended" in the southern Indian Ocean.