A signal thought to come from one of the black boxes of the missing Malaysian plane has been picked up by an aircraft.

The search agency coordinating the search for Flight MH370 said on Thursday an Australian navy P-3 Orion aircraft had detected a signal in the same area sounds were heard on Saturday.

It brings to five the number of signals that have been detected so far.

Associated Press said the aircraft had dropped sound-locating buoys by parachute into an area near where the sounds were last heard.

A ship picked up signals consistent with those emitted by a black box on Saturday and again on Tuesday, allowing searchers to narrow down their search area.                  

Angus Houston, who is heading up the search, said in a statement that the plane had picked up a "possible signal" that may be from a man-made source.

He added: "The acoustic data will require further analysis overnight."

The Australian naval ship ADV Ocean Shield, which picked up the first four 'pings', has been joined by Britain's HMS Echo and the Chinese ship Haixun 01.

They are searching an area of the southern Indian Ocean 1,670km (1,040 miles) from Perth after the plan went missing on route from Kuala Lumpur to Beijing on March 8.