SYDNEY, Australia, April 11 -- Australian Prime Minister Tony Abbott said Friday that he is confident the signals captured over the past days were from the black box of the missing Malaysian flight.

According to reports of the local ABC news and Sky news, he told reporters in Shanghai that the search area has been "significantly narrowed because Australia now had a series of detections and some for quite long period of time."

"We are very confident the signals are from the black box," Abbott was quoted as saying.

However, reporters from ABC news said on their twitter, citing "informed source," that it was "untrue" that the MH370 black box had been located.

A Royal Australian Air Force (RAAF)AP-3C Orion aircraft detected a possible signal in the vicinity of the Australian Defence Vessel Ocean Shield on Thursday.

The Joint Agency Coordination Center (JACC), which leads the search for the missing jetliner, said in a statement the signal was not related to the black box after analysis.

The JACC said that there has been no major breakthrough so far in the search for MH370.