Two pieces of debris found on the beaches of South Africa and Mauritius in March are "almost certainly" from the missing Malaysia Airlines Flight MH370, the Australian Transport Safety Bureau said Thursday. The report comes days after Australian authorities confirmed the identification of two other debris — Part 1 and Part 2 — found in the southeast African nation of Mozambique.

The two new debris pieces — designated as Part 3 and Part 4 — were independently found on March 22 and March 30 on beaches at Mossel Bay, South Africa, and Rodrigues Island in Mauritius, respectively, the ATSB, which is leading the search for Flight MH370, said. 

"Part number 3 was initially identified from the partial Rolls-Royce stencil as a segment from an aircraft engine cowling. The panel thickness, materials and construction conformed to the applicable drawings for Boeing 777 engine cowlings," ATSB said in its report.

Australian investigators said that the stencil was consistent with that developed and used by Malaysia Airlines and closely matched with similar stencils on other Boeing 777 aircraft. The report also shared the photo of the recovered piece compared with Boeing 777 engine cowling stencils.

Part 3 mh370 Comparison of Boeing 777 engine cowling stencils. Photo: Australian Transport Safety Bureau

The Part 4 was "preliminarily identified by the decorative laminate as an interior panel from the main cabin," ATSB said, adding that "the location of a piano hinge on the part surface was consistent with a work-table support leg, utilized on the exterior" of Malaysia Airlines' Boeing 777 jet's closet panel.

"The part materials, dimensions, construction and fasteners were all consistent with the drawing for the panel assembly and matched that installed on other MAB Boeing 777 aircraft at the Door R1 location," ATSB said, showing a comparison of the recovered item with Boeing 777 Door R1 panel assembly.

Part 4 mh370 Comparison of recovered item with MAB Boeing 777 Door R1 panel assembly. Photo: Australian Transport Safety Bureau

Last month, ATSB said that two items from Mozambique, which were found on Dec. 27, 2015, and Feb. 27, 2016, provided almost irrefutable evidence that the parts were from the missing Boeing 777.

In July 2015, a flaperon belonging to Flight MH370 turned up on the French-controlled Réunion Island in the Indian Ocean.

The search for Flight MH370 has been ongoing in a remote part of the southern Indian Ocean for more than two years and is expected to be called off in July. More than 40,000 square miles of the total search area of 46,332 square miles has been scoured so far.

After months of search, which has cost nearly $70 million, authorities are yet to unravel the mystery behind the disappearance of Flight MH370, which went off radar on March 8, 2014, with 239 people on board while on its way from Kuala Lumpur to Beijing.