SYDNEY, March 20 (Xinhua) -- Four aircraft have been deployed to locate the floating objects in southern Indian Ocean, approximately 2,500 km southwest of Perth, in possible connection with a missing Malaysian jetliner, according to Australian Maritime Safety Authority (AMSA) on Thursday.

AMSA says it is coordinating the search for the missing aircraft, with assistance from the Australian Defence Force, the New Zealand Air Force and the United States Navy.

AMSA's Rescue Coordination Centre (RCC) Australia earlier received satellite imagery of two objects possibly related to the missing Malaysia Airlines flight MH370.

The assessment of these images was provided by the Australian Geospatial Intelligence Organization as a possible indication of debris south of the search area that has been the focus of the search operation.

John Young, AMSA Emergency Response Division, said at a news briefing that the objects are in the vicinity of the search area defined and searched in the past two days.

John Young said the images indicate that one of the objects measures around 24 metres in length.

He said, "The indications to me is of objects that are a reasonable size and probably awash with water bobbing up and down under the surface."

A Royal Australian Air Force (RAAF) Orion aircraft arrived in the area about 1.50 p.m.

A further three aircraft have been tasked by RCC Australia to the area later in the day, including a Royal New Zealand Air Force Orion and United States Navy P8 Poseidon aircraft.

The Poseidon aircraft is expected to arrive at 3 p.m. The second RAAF Orion is expected to depart RAAF Base Pearce at 6 p.m. The New Zealand Orion is due to depart at 8 p.m.

A RAAF C-130 Hercules aircraft has been tasked by RCC Australia to drop datum marker buoys.

These marker buoys assist RCC Australia by providing information about water movement to assist in drift modelling. They will provide an ongoing reference point if the task of relocating the objects becomes protracted.

A merchant ship that responded to a shipping broadcast issued by RCC Australia on Monday is expected to arrive in the area about 6 p.m.

Meanwhile, the HMAS Success is en route to the scene. The ship is equipped to recover any objects located.

Australian Prime Minister Tony Abbott said on Thursday that he had spoken to the Malaysian Prime Minister Najib Razak of the new developments, while warning against drawing any conclusion or hopes on the search.

"We must keep in mind the task of locating these objects will be extremely difficult and it may turn out that they are not related to the search for flight MH370," Abbott said.