A ship searching for the missing Malaysian jet has detected two more underwater signals, raising hopes the wreckage of the plane will be spotted soon, the Australian official in charge of the search said Wednesday.

Angus Houston, the head of a joint agency coordinating the search for the missing plane in the southern Indian Ocean, said that the Australian navy's Ocean Shield picked up the two signals in a sweep on Tuesday.

“I think we are looking in the right area but I am not prepared to confirm anything until such time someone lays eyes on the wreckage,” he said.

The Ocean Shield first detected the sounds late Saturday and early Sunday before losing them, but managed to find them again on Tuesday, Houston said. The ship is equipped with a U.S. Navy towed pinger locator that is designed to pick up signals from a plane's black boxes _ the flight data recorder and cockpit voice recorder.

“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 said at a news conference in Perth, the starting point for the search in the southern Indian Ocean.

“I'm now optimistic that we will find the aircraft, or what is left of the aircraft, in the not too distant future _ but we haven't found it yet, because this is a very challenging business,” he said.

“And I would just like to have that hard evidence ... photograph evidence (before saying). that this is the final resting place of MH370,” Houston said.

Finding the sound again is crucial to narrowing the search area so a small submarine can be deployed to chart a potential debris field on the seafloor, which is about 4,500 meters (14,800 feet) deep. If the autonomous sub was used now with the sparse data collected so far, covering all the potential places from which the pings might have come would take many days.

“The better Ocean Shield can define the area, the easier it will be for the autonomous underwater vehicle to subsequently search for aircraft wreckage,” Houston said.

Malaysia Airlines Flight 370 carrying 239 people went missing March 8 on a trip from Kuala Lumpur, setting off one of aviation's biggest mysteries. The search has shifted from waters off of Vietnam, to the Strait of Malacca and then finally to waters in the southern Indian Ocean as data from radar and satellites was further analyzed.

The locator beacons on the black boxes have a battery life of only about a month _ and Tuesday marked exactly one month since the plane vanished. Once the beacons blink off, locating the black boxes in such deep water would be an immensely difficult, if not impossible, task. (AP)