Australian Prime Minister says searchers hunting for the missing Malaysian jetliner are confident underwater signals that have been picked up are coming from the jet's black box.

Australian Prime Minister says searchers hunting for the missing Malaysian jetliner are confident underwater signals that have been picked up are coming from the jet's black box.?

Tony Abbott told reporters that Australian authorities are confident they know the location of the black box from the plane. But he warned the signal from what is believed to be the plane's black box was fading.

Now, the search area has been refined with the help of new "pings". Sophisticated instruments are focusing on a refined area and officials are optimistic that the plane will soon be found.

Meanwhile, the chief coordinator of the joint agency coordination center, Air Chief Marshal Angus Houston said an initial assessment of the possible "fifth ping" detected by an aircraft yesterday has been determined not to be related to an aircraft underwater locator beacon.