The seabed search for the missing Malaysia Airlines jet is set to widen as a sonar scan of the most likely crash site deep beneath the Indian Ocean nears completion without yielding a single clue, authorities said on Friday.
Meanwhile in Beijing, about 50 relatives of Chinese passengers on the plane on Friday continued a sit-in protest outside the Malaysian embassy after officials failed to show up to update them on the search.
The Australian search co-ordinationcentre said a robotic submarine had scanned 95 per cent of a 310-square-kilometre (120-square-mile) search area since last week but had found nothing of interest. The U.S. Navy's Bluefin 21 is creating a three-dimensional sonar map of the ocean floor near where signals consistent with airplane black boxes were heard on April 8.
The search area is a circle with a 10-kilometre (6-mile) radius 4.5 kilometres (2.8 miles) deep off the west Australian coast. The search of the target area is scheduled to be completed within days.
"If no contacts of interest are made, Bluefin 21 will continue to examine the areas adjacent to the 10-kilometre radius," the centre said in a statement.
"We are currently consulting very closely with our international partners on the best way to continue the search into the future," it added, referring to Malaysia, United States and China.
Malaysian Prime Minister Najib Razak told CNN on Thursday that his government will release a preliminary report on the plane's disappearance next week.
The report has already been sent to the United Nation's International Civil Aviation Organization, but has yet to be made available to the public, CNN reported.
The Malaysian government, which has primary responsibility for the investigation, has been accused of mismanaging the search, concealing information about the tragedy and of being too slow to update families of the missing on developments.
In Beijing, the relatives had marched to the Malaysian embassy from their hotel Thursday night after Malaysian officials failed to show up for a promised briefing.
"We keep on waiting because we want the news," said Steve Wang, whose parents were aboard the flight and who has served as a representative for the relatives.
"What we are concerned about is where is the plane, and where are our loved ones," Wang said.