A Chinese military plane reported sighting three objects in Saturday's search, the Australian Maritime Safety Authority (AMSA) said in a statement, while a Royal Australian Air Force (RAAF) P3 Orion spotted multiple objects in a different part of the search area.
The items spotted by the Chinese aircraft were reported by the official Xinhua news agency as being white, red and orange respectively.
The objects cannot be confirmed or discounted as being from MH370 until they are relocated and recovered by ships.
AMSA said Chinese boat Haixun 01 and Australian Navy ship HMAS Success retrieved a number of objects from the ocean that were spotted by aircraft on Friday, but it said no objects confirmed to be related to MH370 have been recovered.
Four ships and eight aircraft were involved in Saturday's search.
The captain of one of those aircraft, a RAAF plane, reported finding nothing of significance.
"The weather in the area was reasonably good - most of the area we were able to see four or five kilometres or more," Flight Lieutenant Russell Adams said.
"The process we go through is everybody on board the aircraft will hear the 'mark, mark, mark' call, up the front from the flight station [and] we'll drop a smoke buoy or flare, which emits smoke for about 45 minutes.
"At the same time the tactical coordinator is going to use a button on the aircraft system that will drop a GPS point. We'll then attempt to maintain visual contact with that object that has been seen and reposition the aircraft to get photographs of it.
"Once we've got photographs of the object we'll be able to send them off for analysis and if there is a vessel in the area... they can recover the object and analyse it from there."
Five more ships are due to arrive in the search area on Sunday.
Meanwhile, two Malaysian C-130 Hercules have joined the search - the first time Malaysian aircraft have been involved in the Australian search.
The Australian navy ship HMAS Toowoomba left Perth late on Saturday to join the search. It is carrying a Seahawk helicopter, but will not reach the search zone for several days.
It comes as the Ocean Shield, an Australian Navy Ship that has been fitted with US black box recovery equipment, is set to head to the search area on Monday.
The black box emits a ping that can be picked up from an ocean depth of just over 4 kilometres, but the batteries powering the signal last just 30 days and are set to run out on April 7.
Australia ready to offer any assistance needed: Abbott
Australian officials are reportedly pushing to take the primary role in the crash investigation and for the efforts to be based in Perth.
Prime Minister Tony Abbott says each nation involved in the search is paying its own expenses, but Australia is willing to offer any assistance that is needed.
"While the prime responsibility rests with Malaysia, Australia is ready to shoulder as much of the responsibility as countries wish us to take," he said.
Malaysian authorities have come under fire several times throughout the search operation, most recently from relatives of the Chinese passengers on the flight who are now demanding China hold its own inquiry.
The families of the Chinese passengers have written to Beijing's envoy in Kuala Lumpur, denouncing Malaysia's handling of the search and asking the Chinese government to set up its own investigation office.
News of the letter comes as a committee set up by the relatives of the Chinese passengers has begun talks with lawyers about a potential lawsuit against Malaysia Airlines.
After meeting with some of the relatives on Saturday, Malaysia's acting transport minister said he understands their feelings.
"I think that is not an unreasonable request for us to continue our prayers, no matter how remote," Hishammuddin Hussein said.
"All I can say is that I can continue only with the leads that we have."
Mr Hishammuddin has defended the way the country had handled the investigation, saying there was nothing he would have done differently.
"I think, like I said in our earlier press conference, no matter what has been thrown and labelled at us, history will judge us as a country that has been very responsible," he said on Friday.
"We have corroborated any evidence that we have received. We have made sure that no stones are unturned."
New search zone declared on Friday
The search shifted closer to the West Australian coast on Friday after a "credible lead" indicated the plane did not travel as far south into the Indian Ocean as first thought.
The zone is not located in the Roaring 40s area, which frequently creates adverse weather conditions.
AMSA said the shift closer to the WA coast was based on further analysis of data captured between the South China Sea and the Strait of Malacca before radar contact was lost.
The information, provided by the international investigation team in Malaysia, suggested the plane was travelling at a higher speed than previously thought, which would increase fuel use and cut the distance it could travel.
The Australian Transport Safety Bureau (ATSB) said information suggested the plane was travelling at "close to constant speed".
"The information provided by the international investigative team is the most credible lead we currently have in the search for aircraft wreckage," the bureau's Martin Dolan said.
"However, this information needs to be continually adjusted for the length of time elapsed since the aircraft went missing and the likely drift of any wreckage floating on the ocean surface."