Malaysia will release a preliminary report next week on the disappearance of flight MH370, Prime Minister Najib Razak said, as his government battles criticism over the transparency of its investigation.

"I have directed an internal investigation team of experts to look at the report, and there is a likelihood that next week we could release the report," Najib told CNN in an interview aired late Thursday.

Philippine forces on Wednesday arrested a Muslim extremist believed to have taken part in the kidnapping of 21 people from a Malaysian resort in 2000, a senior commander said.

Such cross-border kidnappings have become more common recently with militants from the lawless southern Philippines traveling to nearby Malaysia, where there are many dive resorts popular with foreign tourists.

Armed pirates boarded a Singapore-managed oil tanker in the Strait of Malacca, kidnapping three Indonesian crew and stealing some of the vessel's shipment of diesel fuel, the International Maritime Bureau said Wednesday.

The attack occurred early Tuesday off Malaysia's west coast, said Noel Choong, head of IMB's Kuala Lumpur-based piracy reporting center. The diesel oil tanker was believed to be en route to Myanmar.

Australia said Wednesday cost was not a concern in the search for Malaysia Airlines Flight MH370, after the mini-sub plumbing the depths of the Indian Ocean for wreckage ended its ninth mission empty-handed.

Australia is leading the multinational search for the Boeing 777 which vanished on March 8 carrying 239 people, and is bearing many of the costs of the mission expected to be the most expensive in aviation history.

The aerial search for missing Malaysian Airlines Flight MH370 was suspended Tuesday due to a tropical cyclone, but not before several aircraft had departed on the mission, Australian officials said.

Up to 10 military aircraft had been scheduled to fly over the Indian Ocean in hopes of spotting clues as to the fate of the Boeing 777, which vanished on March 8 carrying 239 people.

Malaysia's opposition leader Anwar Ibrahim said Monday a meeting with U.S. President Barack Obama during a coming visit to Malaysia would have been "consistent with U.S. democratic ideals," after Washington said there would be no such encounter.

But Anwar, who was convicted of sodomy in March and whose opposition is engaged in a fierce political battle with Malaysia's longtime government, stopped short of criticizing the U.S. president.

A passenger bus plunged into a ravine after leaving a Malaysian island resort, killing a British man and injuring 40 others, mostly foreign tourists, police said Monday.

The chartered bus bound for neighbouring Singapore lost control and skidded, falling into the 10-metre-deep (33 feet) ravine in the east coast state of Pahang on Sunday, district police chief Yahaya Othman said.

A Malaysia Airlines plane with 166 people aboard was forced to make an emergency landing in Kuala Lumpur early Monday in another blow to the flag-carrier's safety image after the loss of flight MH370.

Flight MH192, bound for Bangalore in India, turned back to Kuala Lumpur shortly after it was discovered that a tire had burst on take-off, the airline said.

Two-thirds of the planned underwater search for missing Malaysia Airlines flight MH370 has been completed, with no signs so far of the jet, Australian officials said Monday.

As many as 10 military aircraft and 11 ships are taking part in the search for the aircraft, which was carrying 239 people when it vanished on March 8 en route from Kuala Lumpur to Beijing.

The intense global scrutiny brought upon Malaysia's government over the fate of flight MH370 has tossed a wild card into its controversial efforts to send opposition leader Anwar Ibrahim back to jail.

Just hours before the Malaysia Airlines plane disappeared on March 8, a court overturned Anwar's 2012 acquittal on sodomy charges he says are false and part of a long-running government attempt to wreck his political career.