As search and rescue efforts for the missing Malaysia Airlines Boeing 777-200 look set to enter into the fourth day, Malaysia says it has not tightened security across its airports as it does not yet deem the MH370 case as a "security threat".

Speaking at a press conference in Kuala Lumpur, its defence minister Hishammuddin Hussein says that part of its investigation includes looking into the mental health of the pilots on board the aircraft, a practice not uncommon in the aviation industry.

"Internationally this is not something the aviation industry is not familiar with. There's been incidents like this before and the normal procedure is to look into the mental health of not only the pilots but also whoever else is involved," he says.

He adds that China has also sent a delegation to Kuala Lumpur to assist Malaysia in three aspects: search and rescue, identifying the two passengers who boarded using fake passports, and also dealing with families of those on board MH370. Chinese presence in the investigation however does not mean that those traveled with the fake passports were Chinese citizens, says Hishammuddin.

He adds that details of the two passengers, including their background and biometric data have also been given to international intelligence agencies and their pictures could soon be released to the public.

Hishammuddin also confirmed that Vietnamese searchers have reported spotting what looks like an “inverted life craft”, and that vessels have been deployed to identify the objects. There are no updates on lab analysis of the oil slicks found on the South China Sea, he adds.

Asked about the five passengers who checked-in but did not board MH370, Hishammuddin says investigations are ongoing but that he could not disclose further information. Pressed on why the stolen passports were not checked against the Interpol list, he rebutted that there are over 40 million names on the list.

The MAS 777, registered 9M-MRO, was on the Kuala Lumpur-Beijing route, when it lost contact with the Subang Air Traffic Control at around 01:30 local time on 8 March. Its last reported position was over an area between Malaysia and Vietnam.

Source: Cirium Dashboard