Families of passengers on board the missing Malaysian Airlines plane have threatened to go on hunger strike, as their desperate wait for news continues. The threat from relatives waiting in Beijing came as it emerged two-thirds of those on flight MH370 have been cleared of any links to terrorism, according to officials.
Background checks on all 154 Chinese passengers have not uncovered any evidence suggesting a plot to hijack or bring down the aircraft, Huang Huikang, the Chinese ambassador to Malaysia, said.
It appears to discount one theory that Uighur separatists - the group blamed for an attack in Beijing's Tiananmen Square last October and the massacre at Kunming railway station earlier this month - might have been involved in the plane's disappearance.
There has been no trace of the Boeing 777 since it disappeared less than one hour into its flight from Kuala Lumpur to Beijing with 239 people on board. The aircraft's tracking devices were deliberately switched off, allowing it to travel almost undetected.
Satellite data suggests the plane flew for at least seven hours and could have ended up anywhere from central Asia to the southern reaches of the Indian Ocean.
It has prompted an unprecedented search involving teams from some 26 countries, who are scouring huge swathes of land and ocean for any sign of the aircraft.
Mr. Huang said searches are now under way in China - part of which crosses a northern corridor along which the plane may have flown.
Meanwhile, investigators continue to probe the background of pilots Zaharie Ahmad Shah and Fariq Abdul Hamid, as well as ground engineers who worked on the aircraft before it took off.
The homes of both pilots have been searched and a flight simulator belonging to Mr. Zaharie seized.
It is believed Mr. Hamid made the last communication from the aircraft, calmly telling air traffic controllers as the plane passed into Vietnamese air space: "All right, good night."
Malaysian Defence and acting Transport Minister Hishammuddin Hussein said "The fact that there was no distress signal, no ransom notes, no parties claiming responsibility, there is always hope".
While a former Malaysian Transport Minister Ong Tee Keat has said the International Civil Aviation Organisation (ICAO) - a UN body - should take on the investigation to ensure there are no cover-ups or withholding of information.
He said he was not alleging a cover-up, but said transparency is needed. He also said better coordination is needed among Malaysian government agencies and between countries to help find the plane.