Search area narrowed

• "The acoustic data will require further analysis," search agency's chief coordinator says


• The signal was detected near the Australian vessel Ocean Shield


• Efforts are being made to pinpoint the location of the beacons

(CNN) -- A plane has detected a possible signal from sonar buoys equipped to detect signals from the locator beacons on the so-called black boxes from missing Malaysia Airlines Flight 370, according to the Australian agency coordinating the search.

"The acoustic data will require further analysis overnight but shows potential of being from a man-made source," retired Air Chief Marshal Angus Houston, the agency's chief coordinator, said Thursday.

The possible signal was detected near the Australian ship Ocean Shield, said the Joint Agency Coordination Centre.

Crews have been narrowing the search area in the Indian Ocean.

Up to 10 military aircraft, four civil aircraft and 13 ships were to assist in Thursday's search for the Boeing 777-200ER, which was carrying 239 people when it appeared to vanish on March 8 on a fight from Kuala Lumpur, Malaysia, to Beijing.

Aircraft and ships spotted a number of objects during Wednesday's search, but could recover only a small number, none of which appeared linked to MH370, the JACC said.

Thursday's search area is about 22,364 square miles (57,923 square kilometers), centered some 1,417 miles (2,280 kilometers) northwest of Perth.

Thursday's underwater search area was bracketed Thursday by the Ocean Shield at the northern end of the search area and the Chinese ship Haixun 01 and HMS Echo at the southern end.