The mystery over the missing Malaysian aircraft with 239 people on board continued for the third day on Monday even as the multinational search operations to look for the wreckage widened to cover the Andaman Sea near Thailand's border.
"Unfortunately, we have not found anything that appears to be objects from the aircraft, let alone the aircraft itself," Azharuddin Abdul Rahman, head of Malaysia's Department of Civil Aviation (DCA), said at a news conference.
Hopes for finding some clue about the missing jet arose when authorities reported traces of oil slick and some object floating in the sea in the area where the aircraft went missing. But the reports were denied on Monday.
"This unprecedented missing aircraft mystery -- it is mystifying and we are increasing our efforts to do what we have to do," he said.
Five Indians and a Canadian of Indian-origin were among the 239 people on board the Beijing-bound flight MH370 when it disappeared over the South China Sea one hour after taking off from Kuala Lumpur.
Thirty four planes, 40 ships and teams from ten countries are involved in search operations. Rahman said the DCA is expanding the area of search operations in the next few days. He said right now they just cannot speculate what happened to the aircraft as it has not been found.
The initial search zone spread over a 50 nautical miles (92 kilometres) radius around the point where flight vanished. Malaysian authorities announced it was doubling the size of the search area to 100 nautical miles.
Rahman said that besides scouring in waters between Malaysia and Vietnam, authorities were also searching on land in Malaysia and off western Malaysia.
The focus has also shifted to the Andaman Sea, near Thailand's border, after radar data indicated the plane may have turned around to head back to Kuala Lumpur.
Malaysia on Sunday launched a terror probe into the disappearance of the plane.
The probe was launched after it emerged that two passengers boarded the flight with stolen passports of an Italian and Austrian. One of the two suspects, who travelled on the plane on stolen passports has been identified.
Rahman said they are probing a stolen passport syndicate and confirmed that the two suspects were not Asian-looking.
Rahman said investigators were pursuing "every angle" to explain its disappearance, including hijacking. Counter- terrorism agencies and the FBI are also involved in the probe.