Many Chinese relatives of passengers onboard the missing Malaysia Airlines flight MH370 reacted with anger and disbelief after Malaysian Prime Minister Najib Razak confirmed that the piece of debris found last week near La Reunion Island in the southern Indian Ocean came from the vanished airliner.

Hao Yuexin, 63, cries after Malaysian Prime Minister Najib Razak announced that experts "conclusively" confirmed that the debris found on Reunion Island was from MH370. Hao's son, Zhang Jianwu, was onboard the aircraft.[Photo/China Daily]

Almost 20 relatives marched to the Beijing office of Malaysia Airlines on Thursday to make their voices heard, before moving onto the Beijing office of Boeing to demand more details about the investigation.

"We don't care about the flight wreckage, we want the people on the flight," said Zhang Yongli, a 64-year-old Beijing native, whose daughter was onboard the flight.

The Boeing 777 disappeared on March 8 last year with 239 passengers and crew members on its way to Beijing from Kuala Lumpur, the capital of Malaysia. The plane has not been found despite a massive surface and underwater search, in what has become one of the biggest mysteries in aviation history.

On July 29, a piece of plane wreckage was found on Reunion Island, a volcanic island near Madagascar, roughly 3,700 kilometers from the broad expanse of the southern Indian Ocean off Australia where search efforts have focused.

The aircraft has not been found.

Zhang Jianyi, a 59-year-old Anhui native whose daughter and son-in-law and their son were on the flight, said he would not believe the finding because many other parts, such as chairs and life jackets, could have been more easily found than the wing part.

"There will be lots of debris. But so far only a single piece of wreckage has been found," he said.

"If local cleaners can make a discovery, so can we. I believe we should be given a part to play if there has been a breakthrough with the discovery," Zhang said.

The Chinese government expressed grief and sorrow for those onboard the flight and extended profound sympathy and condolences to their families on Thursday. It requested that Malaysia continue to investigate the cause of the accident, provide the families with necessary help and uphold their lawful rights and interests, Chinese Foreign Ministry spokeswoman Hua Chunying said in a statement.

According to the Australia-led Joint Agency Coordination Centre established to search for the missing plane, the drift model indicates that if there is any more floating debris from MH370, it could be anywhere in hundreds of thousands of square kilometers in the Indian Ocean.

The debris was shipped to France and experts confirmed it to be from the trailing edge of a Boeing 777 wing.

Malaysian Prime Minister Najib Razak announced during a news conference in Kuala Lumpur earlier on Thursday that an international team of experts has "conclusively" confirmed that the aircraft debris found on Reunion Island was from MH370.

Just a few hours after Najib's confirmation, the coordination center issued a statement saying that it will await further details from the French-led investigation team that is continuing to finalize its investigation of the debris.

Australian Deputy Prime Minister Warren Truss added that the finding of wreckage on Reunion Island is consistent with the current search area, and so thorough and methodical search efforts will continue there.

Li Lianxiu, whose granddaughter was on the flight, said the relatives wondered why Malaysian authorities made the statement about the identification of the debris before statements from the French investigation teams, which are leading the identification work on the debris.

Many relatives also said they want to go to Reunion Island, yet neither Malaysia Airlines nor Malaysian authorities have contacted them to facilitate the journey.

Zhang Qian, 30, whose husband was onboard the plane, said she has quit her job so she can commit herself to finding the "truth" about MH370.