Two pieces of debris found in South Africa and on Rodrigues Island near Mauritius ware "almost certainly" from missing flight MH370.
The two pieces now brings the total number of pieces thought to come from the missing Malaysian Airlines plane to five.
The aircraft disappeared more than two years ago with 239 people on board. An extensive underwater search of a wide area of the Indian Ocean off Australia's west coast has so far been fruitless.
While the discovery of the debris supports authorities' assertion that the plane went down in the Indian Ocean, none of the pieces of debris have offered any clues into exactly where and why the aircraft crashed.
Malaysian Transport Minister Liow Tiong Lai said the two new parts were an engine cowling piece with a partial Rolls-Royce logo and an interior panel piece from an aircraft cabin.
Mr Liow said an international team of experts in Australia who examined the debris concluded that both pieces were consistent with panels found on a Malaysia Airlines' Boeing 777 aircraft.
He added: "As such, the team has confirmed that both pieces of debris from South Africa and Rodrigues Island are almost certainly from MH370."
All five pieces have been found in various spots around the Indian Ocean. Last year, a wing part from the plane washed ashore on France's Reunion Island. In March, investigators confirmed two pieces of debris found along Mozambique's coast were almost certainly from the aircraft.
The jet, which vanished on March 8, 2014, while flying from Kuala Lumpur to Beijing, is believed to have crashed somewhere in a remote stretch of the southern Indian Ocean about 1,800 kilometers (1,100 miles) off Australia's west coast.
Authorities had predicted that any debris from the plane that isn't on the ocean floor would eventually be carried by currents to the east coast of Africa.
Search crews have combed more than 105,000 square kilometers (40,000 square miles) of an underwater search zone with no result. The sweep of the area is expected to be finished by the end of June.
