THE wailing mother of a Chinese passenger on a missing jet was carried out of a media briefing where she had been protesting over a lack of information.

Malaysia Airlines Flight MH370 disappeared 12 days ago from air traffic control screens off Malaysia's east coast early on March 8, after taking off from Kuala Lumpur bound for Beijing.

Several relatives of passengers unfurled a banner and began shouting to reporters before they were led away by security guards, with one woman wailing in grief.

The woman, who said her son had been on Flight MH370, said: "They are just saying wait for information. We don't know how long we have to wait.

"Why won't they give us an explanation?

"My son. It has been 12 days. I have been here 10 days, every time we ask a question they don't give us answers."

A second woman yelled in protest: "We call on the Malaysian government to give us information immediately.

"There is no information, just endless searching.

"We are not satisfied with the Malaysian government's conduct. We don't need the Malaysian government to take care of us.

"What we need is the truth. We need to know where the plane is."

Asked about the protest, Acting Transport Minister Hishammuddin Hussein said Malaysia was sending another "high-level" team to Beijing to improve communications with relatives.

Investigators now believe the jetliner flew towards the southern Indian Ocean, although a reported sighting over the Maldives has been discounted.