A Royal Australian Air Force (RAAF) AP-3C Orion aircraft has detected a possible signal consistant with the missing jet in the vicinity of the Australian Defence Vessel (ADV) Ocean Shield, an official confirmed Thursday.
"The acoustic data will require further analysis overnight but shows potential of being from a man-made source," said Angus Houston, chief coordinator of the Joint Agency Coordination Center (JACC).
Joint Agency Coordination Center (JACC) is leading the multi-national operation to search for the missing Malaysian Airlines jetliner that vanished mysteriously with 239 on board.
According to JACC figures, the ADV Ocean Shield is narrowing down Thursday's search area from 75,000 square km to 57,923 km, which lies approximately 2,280 km northwest of Perth, Xinhua reported.
The ADV Ocean Shield detected four signals Saturday and Sunday.
"Hopefully with lots of transmissions we'll have a tight, small area and hopefully in a matter of days we will be able to find something on the bottom that might confirm that this is the last resting place of MH370," Houston was quoted as saying.
Up to 14 planes and 13 ships have joined in Thursday's search for the missing Malaysia Airlines flight MH370.
Except for the search operation on the ocean surface, the underwater search also continued Thursday, with the Ocean Shield at the northern end of the defined search area, and Chinese ships Haixun 01 and HMS Echo at the southern end.
Two separate signals were detected Sunday by a US pinger locator being towed by the ADV Ocean Shield in the Indian Ocean search area, about 1,700 km northwest of Perth.
The first detection of the signal lasted for two hours and 20 minutes. After few hours, the second signal was detected which lasted for 13 minutes.
The two signals were about 1800 metres apart.
The ADV Ocean Shield detection Sunday came shortly after a Chinese patrol vessel, the Haixun One Zero, reported detecting two pulse signals Friday night, and then again Saturday at a frequency consistent with black box technology.
The Malaysia Airlines flight MH370 vanished mysteriously about an hour after taking off for Beijing from Kuala Lumpur shortly after midnight March 8.
The Boeing 777-200ER was scheduled to land in Beijing the same day. The 227 passengers on board included five Indians, 154 Chinese and 38 Malaysians.
Despite extensive scouring of the remote southern Indian Ocean area by planes and ships off the coast of Perth, where the plane is believed to have crashed, no trace has been found.