Five out of 10 aircraft hunting for Malaysia Airlines Flight 370 found objects of various colours, the Australian Maritime Safety Authority (Amsa) said.
It was not clear whether the objects were from the plane, but they included two that were blue and grey - among the colours of the missing plane.
A Chinese patrol ship in the area will attempt to locate the objects tomorrow, Amsa said.
The three-week hunt for the jet has been filled with possible sightings, with hundreds of objects identified by satellite and others by plane, but so far not a single piece of debris has been confirmed.
Australian officials said they turned away from the old search area, which they had combed for a week, because a new analysis of radar data suggested the plane had flown faster and therefore ran out of fuel more quickly than previously estimated.
Planes and ships spent a week searching about 1550 miles south-west of Perth, Australia. Now they are searching about 1150 miles west of the city.
The new search area is about 80% smaller than the previous one at about 123,000 square miles - roughly the size of Poland.
The radar data that was re-analysed was received soon after Flight 370 lost communications and veered from its scheduled path on March 8. The Beijing-bound flight carrying 239 people turned around soon after taking off from Kuala Lumpur, flew west towards the Strait of Malacca and disappeared from radar.
The search area has changed several times since the plane vanished as experts analysed a frustratingly small amount of data from the aircraft, including the radar signals and "pings" that a satellite picked up for several hours after radar and voice contact was lost.
Martin Dolan, chief commissioner of the Australian Transport Safety Bureau, said the search for surface debris would given an indication of where the main wreckage would be.