BEIJING (AFP) - Malaysian authorities need to "step up their efforts" over an aeroplane that disappeared with more than 150 Chinese on board, Beijing said on Monday.

"The Malaysian side attaches importance to the incident with a sincere attitude, but in light of the situation, the Malaysian side needs to step up their efforts," foreign ministry spokesman Qin Gang told reporters at a regular briefing.

Some passengers' family members have expressed anger and frustration with the response effort, criticising Malaysia Airlines as well as authorities in Beijing and Kuala Lumpur for a lack of information surrounding the disappearance of MH370.

Mr Qin said that while Beijing believes Malaysia is making its best efforts, "two days after the incident, we still hope the Malaysian side will fully understand the emergent mood of the Chinese family members of the passengers".

"We will continue with our work, particularly in urging the Malaysian side in search and rescue and other follow-up issues," he said.