SYDNEY (AP) -- Search crews hunting for Malaysia Airlines Flight 370 in the desolate waters off western Australia have discovered a shipwreck, officials said Wednesday.
The unexpected find came when sonar equipment on board a search vessel scouring the Indian Ocean for the missing jetliner detected a cluster of objects nearly 4 kilometers (2.5 miles) below the surface, according to a statement from the Australian Transport Safety Bureau, which is heading up the hunt.
Although officials suspected after finding the objects that they were probably not from the Boeing 777, which vanished on March 8, 2014, they decided to take a closer look just in case. A second ship sent down an autonomous underwater vehicle -- essentially, an unmanned sub -- which revealed a large number of small objects and several larger items, the biggest 6 meters (20 feet) long.
The debris field appeared to be man-made, but wasn't typical of an aircraft. Still, crews sent down a camera to be sure.
Analysis of the photos revealed this week that the debris came from a previously uncharted shipwreck. Marine archaeologists are now examining the photos, which include an image of an anchor and what appear to be lumps of coal, to see whether they can identify the ship. It was not immediately clear when the sonar first spotted the wreckage.
"It's a fascinating find, but it's not what we're looking for," Peter Foley, the ATSB's Director of the Operational Search for Flight 370, said in a statement. "We're not pausing in the search for MH370, in fact the vessels have already moved on to continue the mission."
Last month, officials announced that they would expand the search area for Flight 370 by another 60,000 square kilometers (23,000 square miles) in the Indian Ocean if the plane is not found by the end of May. Crews have now covered 75 percent of the original search area and have already moved into the southern portion of the expanded search zone to take advantage of the last dregs of decent weather before winter sets in.
One of the four search vessels, which has the autonomous underwater vehicle on board, has withdrawn from the hunt because the worsening weather has made it too difficult for crews to launch the sub.