The most recent satellite images of two objects that could be related to missing Malaysia Airlines flight MH370 are "credible," but authorities have yet to confirm whether they form part of the plane's debris, Malaysia's transport minister said on Thursday.
Speaking at a press conference, Hishammuddin Hussein said four aircraft had been sent to the southern Indian Ocean following the sighting by Australian authorities.
The objects - the largest of which was estimated to measure up to 24 meters - were seen approximately 2,500 km (1,500 miles) south of Perth, authorities said, and could be submerged in several thousand meters of water.
But Hussein stressed: "The images were captured by satellite; they may not be related to the aircraft."
The Malaysian minister added that the search of the area was being coordinated by the Australian Defence Force, New Zealand Air Force and U.S. Navy.
"Every effort is being made to locate the objects seen in the satellite imagery," he said. "It must be stressed that these sightings while credible, have still to be confirmed."
At an earlier news conference, John Young, general manager of the emergency response division at the Australian Maritime Safety Authority (AMSA), said the images were "indistinct" but credible enough to redirect resources to the search area.
"I don't want to draw too much from that [satellite image]. This is a lead, it is probably the best lead we have right now, but we need to get there, find them, see them, assess them to know whether this is really meaningful or not," he said. "I caution that they [the objects] will be difficult to find, they may not be associated with the aircraft."
Flight MH370 disappeared on March 8 en route to Beijing from the Malaysian capital Kuala Lumpur with 239 passengers and crew on board. It vanished from civilian air traffic control screens off Malaysia's east coast less than an hour after taking off.
The AMSA said that four aircraft have been re-orientated to locate the objects. Young said one aircraft was already in the area, with a U.S. navy aircraft probably already on site.
Two more aircraft were expected to arrive in the search area later in the day and a merchant ship has also been diverted to help.
"I think it is certainly the most credible sighting that I have heard anything about since we've been at this and I can't imagine how it could be just a false alarm that has very little merit given that it was the [Australian] PM [Prime Minister] that announced it," said Jim Tilmon, a former American Airlines pilot and President & CEO of aviation consulting firm Tilmon Group.
Australia's Prime Minister Tony Abbott told parliament earlier on Thursday that "new and credible information" has come to light in the search for the missing plane and Malaysian authorities confirmed that there was a new lead in the investigation.
The AMSA's Young added that the search effort for the objects could be hampered by poor visibility.
"The focus for AMSA is to continue the search operations with all available ships and aircraft, searching for any signs of the missing aircraft," Young said. "Weather conditions are moderate in the southern Indian Ocean where the search is taking place, however poor visibility has been reported and this will hamper both air and satellite efforts."
Twelve days have passed since the Malaysian jet went missing and an international search effort covers an area roughly the size of Australia, or more than two-thirds the size of the United States.
However, there was a note of caution from Australian authorities. Satellite images released by China last week of objects that were possibly related to the missing plane were not verified.
"They [the Australian authorities] are being understandably cautious given the circumstances, satellite imagery of objects can only reveal so much," Richard Aboulafia, an aerospace analyst at Teal Group, told CNBC.
"What is positive is that Australia and New Zealand have some excellent long-range search assets. I suspect they will get on the scene fairly quick and we will know fairly quickly," he added.
According to the latest updates, investigators believe somebody turned off vital data links and turned the plane west, re-crossing the Malay Peninsula and following a commercial route towards India.
(Read more: MH 370 theories: It's not about entertainment)
U.S. and Malaysian officials believe the aircraft was deliberately diverted. They have played down the possibility that an electrical fire could have prompted pilots to turn off electrics before being overwhelmed by fumes, which has been the subject of widespread online speculation.
In Malaysia, families and friends of loved ones on the missing plane have expressed their anger and frustration at the lack of new leads and information.
- Reuters contributed to this report.