Two more acoustic signals have been picked up by an Australian navy ship in the search for the missing Malaysia Airlines plane.

Officials have described the development as “very encouraging”.

It was revealed on Sunday that two acoustic signals had been picked up by a Chinese ship using hydrophones while Ocean Shield had detected a signal in a different part of the Indian Ocean search zone.

Retired air chief marshal Angus Houston, who is in charge of co-ordinating the search from Perth, said the Ocean Shield, which is towing a “pinger” detector, had since picked up signals on two separate occasions in the northern part of the search zone.

This is a most promising lead

The first signal held for two hours and 20 minutes before contact was lost.

Two distinct “pinger” returns, consistent with the flight data and cockpit voice recorders, were then audible for 13 minutes, he said.

“This is a most promising lead,” he told reporters on Monday.

But he warned against jumping to any conclusions, saying more information was needed.

“We haven’t found the aircraft yet,” he said.

MH370 with 239 people aboard disappeared on a flight from Kuala Lumpur to Beijing on March 8.