Relatives of Chinese passengers aboard a missing Malaysia Airlines flight reacted with hysteria on Monday after the Malaysian prime minister announced the jet ended its journey in the remote Southern Indian Ocean.

At the Beijing hotel where many of the relatives are staying, family members erupted in shouts and tears after they heard the news, wailing and in some cases dropping to the floor.

One woman screamed out: "It's not possible, it's not possible!" before collapsing.

At least four people were stretchered out, having apparently been overcome with emotion.

Flight MH370 vanished from civilian radar screens less than an hour after take-off from Kuala Lumpur for Beijing with 239 people - more than half Chinese nationals - on board on March 8.

No confirmed sighting of the plane has been made since, but much debris has been found in waters off Australia which might be part of the missing plane.

Malaysian Prime Minister Najib Razak said fresh analysis of satellite information from British company Inmarsat had shown that the last position of the aircraft was in the Indian Ocean west of Perth, Australia.

Several Chinese media outlets reported on their official Weibo microblogs that family members received a text message saying that "we have to assume beyond reasonable doubt" that none of those onboard survived.

China has repeatedly pressed the airline and the Malaysian government to give more information to family members and ensure they are being properly looked after.

Some relatives had threatened hunger strikes and protests in front of the Malaysian embassy to express their anger.