PERTH, Australia, April 9 -- Australian ship Ocean Shield reacquired two more suspicious signals in an intensified search for missing Malaysia Airlines flight MH370, the Australian coordination chief said Wednesday.

"Ocean Shield has been able to reacquire the signals on two more occasions, late yesterday afternoon and later last night," said Angus Houston, head of Australia's Joint Agency Coordination Center (JACC), adding the last signal heard was weak.

Houston said the new detections boosted the hope that "we are searching in the right area," which is approximately 2200 kilometers northwest of Perth.

Ocean Shield, equipped with U.S.-supplied towed pinger locater, heard two suspicious pulse signals on Monday.

Houston said data analysis of the first two signals confirmed that they were consistent with aircraft black boxes and not from a natural origin.

Experts "believe the signals to be consistent with the specification and description of a flight data recorder," Houston told reporters.

Though the new detections were "great lead," Houston cautioned that there is still a long way to go and no final conclusion can be made until "somebody sees the wreckage."

He said the U.S. underwater vehicle will not be sent down to scour the ocean floor until all possibilities of surface search are exhausted.

Up to 11 military aircraft, four civil aircraft and 14 ships joined Wednesday's hunt for MH370 as the search area has been narrowed to about 75,423 square kilometers.