CANBERRA (AFP) - Australia prepared to resume its search Friday for possible plane wreckage floating in a remote and stormy section of the Indian Ocean, as the vast international hunt for a missing passenger jet entered its 13th day.

Surveillance aircraft on Thursday detected a pair of floating objects captured by satellite imagery, which Australia and Malaysia guardedly called a "credible" lead in the baffling mystery surrounding missing Malaysia Airlines Flight 370.

The Australian-led search was due to restart at first light, as a Norwegian merchant ship arrived in the target area about 2,500 kilometres southwest of Perth, after warnings of poor weather conditions and limited visibility.

Four aircraft suspended their search at nightfall Thursday without any sighting of the possible debris after scouring a 23,000-square-kilometre area where the grainy images were snapped, the Australian Maritime Safety Authority said.

Two planes came from Australia, one from New Zealand and one was a US aircraft, while another merchant ship was en route to join Norway's Hoegh St Petersburg merchant ship.

The Australian navy's HMAS Success was also headed for the area, and Britain sent a naval survey ship, HMS Echo.

Australia said the satellite-captured objects - the largest was estimated at 24 metres across - raised hopes of a breakthrough in the Malaysian plane's mysterious disappearance as relatives of the 239 people aboard braced for another emotional roller-coaster.

"We now have a credible lead," Transport Minister Hishammuddin Hussein said during Malaysia's daily briefing on the crisis.

"There remains much work to be done to deploy the assets." Clearly wary of raising hopes following a series of past false leads, Hishammuddin warned of delays in verifying the apparent debris.

The Malaysia Airlines Boeing 777, carrying 227 passengers and 12 crew, vanished in the early hours of March 8 after veering drastically off course over the South China Sea while en route to Beijing.

On Thursday, China's Foreign Ministry said that the missing Malaysian plane did not enter the territory of China according to a Xinhua report.

Investigators say it was deliberately diverted but still don't know by whom, why or where it ended up.