The Australian Maritime Safety Authority (AMSA) updated by midnight Thursday the information about the search operation related to missing Malaysia Airlines flight MH370, saying the four aircraft it commissioned have covered an area of 23,000 square kilometers.

"Four aircraft were tasked by the Australian Maritime Safety Authority on Thursday to a 23,000 square kilometer area about 2, 500 kilometers south-west of Perth," AMSA said in its latest media release.

Two Royal Australia Air Force (RAAF) AP-3C Orions, a U.S. Navy P8 Poseidon, and a Royal New Zealand Air Force P-3K2 Orion were utilized, along with an RAAF C-130J Hercules aircraft.

According to AMSA's earlier release, the C-130J Hercules aircraft was tasked to drop datum marker buoys.

According to the latest release by AMSA's Twitter account, Royal Australian Air Force P3 crew "unable to locate debris," " Cloud and rain limited visibility. Further aircraft to continue search for MH370."

A merchant ship arrived in the search area on Thursday evening. Another merchant ship is en route to the area.

A total of six merchant ships have assisted in the search since a shipping broadcast was issued on Monday night.

The Royal Australian Navy ship HMAS Success is also en route to the search area. But it will take days for it to arrive at the related area.

Earlier Thursday afternoon, Australian Prime Minister Tony Abbott told parliament "new and credible information" had come to light in the search for MH370.

Abbott said he had informed Malaysian Prime Minister Najib Razak of the developments. But he warned against drawing any premature conclusions or hopes on the search.

AMSA confirmed at the press conference that followed that it has received an expert assessment of commercial satellite imagery of objects it suspects may indicate a "debris field" from the flight, floating in the ocean 2,500 kilometers south-west of Perth.

AMSA said the search will continue on Friday.?