Four people, including three foreigners, who turned up after disappearing for more than a week in the South China Sea were found by chance aboard a trespassing Vietnamese trawler, Malaysia's coast guard has said.

Spanish nationals David Hernandes Gasulla and Martha Miguel, Hong Kong citizen Tommy Lam Wai Yin, and Malaysian Armilla Alihassan went missing in their small boat May 2 while on an island-hopping excursion off the Malaysian state of Sabah on Borneo island.

Malaysian authorities are searching for three foreigners who went missing in waters near the Philippines where a spate of recent kidnappings have taken place, a coast guard official said Wednesday.

The official cautioned there was so far no cause to suspect the abduction of the foreigners, who went missing late Monday along with a Malaysian off the state of Sabah on Borneo island.

Mozambican civil aviation authorities on Monday handed over suspected debris from missing flight MH370 to Malaysian experts after the piece was found by an American amateur investigator.

The debris, which was picked up on the Mozambique coastline, could provide fresh clues into the mystery of the Malaysia Airlines flight, which disappeared two years ago.

Leaders from across Malaysia's political spectrum joined forces Friday to call for the removal of scandal-hit premier Najib Razak, in a sharp escalation of a festering corruption crisis.

"We call upon all Malaysians, irrespective of race, religion, political situation, creed or parties, young and old, to join us in saving Malaysia from the government headed by Najib Razak," read a joint statement endorsed by heavyweights from the ruling party, opposition, and civil-society groups.

Australian and Malaysian officials were moving to retrieve and examine suspected aircraft wreckage found on the east African coast to quickly determine whether it came from missing flight MH370, Malaysia's transport minister said Thursday.

The one-meter long (three-foot) piece of debris found on a Mozambique beach could provide fresh clues into the mystery of the Malaysia Airlines flight, which disappeared two years ago.

An international team of investigators probing the loss of flight MH370 will issue a statement next week on the second anniversary of the plane's disappearance, a government official said Thursday.

"On 8 March, the MH370 investigating team will release an interim statement," Malaysian Transport Minister Liow Tiong Lai told reporters in Kuala Lumpur.

There is a "high possibility" that aircraft debris reportedly found off the coast of Mozambique came from a Boeing 777, Malaysia's transport minister said Wednesday, the same aircraft model as missing flight MH370.

"Based an early reports, high possibility debris found in Mozambique belongs to a B777," Liow Tiong Lai said on his Twitter feed.

Two family members of a Chinese passenger who disappeared on flight MH370 have filed suit against Malaysia Airlines, a Beijing court said Friday, as a two-year deadline to do so approaches on March 8.

The case was successfully registered at the Beijing Rail Transportation Court, the court said in a statement on its official website.

Malaysia confirmed Tuesday that debris found on the coast of southern Thailand was not from Malaysia Airlines flight MH370, laying to rest one question but leaving the fate of the missing airliner still shrouded in mystery.

The discovery of the metal panel on the shores of the Gulf of Thailand on Saturday ignited intense speculation over whether a fresh clue had been found in the MH370 enigma, whose bizarre disappearance continues to haunt the aviation world.

Malaysian police said on Sunday they had arrested seven alleged Islamic State (IS) militants plotting violence, one of whom was in contact with an extremist blamed for the deadly Jakarta attack.

Thirty rounds of ammunition was also seized along with books and videos about jihad and an IS flag during a series of raids around the country since Friday, national police chief Khalid Abu Bakar said in a statement.