The US navy has ordered a ship to the Indian Ocean to search for a missing Malaysian airliner amid reports the plane kept "pinging" a satellite after losing radar contact.
The focus of search efforts shifted on Thursday from the South China Sea after the US said "new information" indicated that Malaysia Airlines Flight MH370, with 239 on board, may have gone down to the west in the Indian Ocean.
Malaysian authorities expanded their search for the plane westward towards India, based on reports that it could have flown for hours after it last made contact.
Hishammuddin Hussein, the Malaysian transport minister, said his government was asking for radar data from India and other neighbouring countries.
For its part, India used heat sensors on flights over hundreds of uninhabited Andaman Sea islands on Friday and will expand its search futher west into the Bay of Bengal, officials said.
Two Indian naval ships and two coast guard vessels also scoured the surrounding seas without finding evidence of the plane, according to Colonel Harmit Singh, a spokesman for India's navy.
Jay Carney, a spokesman for the White House, said: "It's my understanding that based on some new information that's not necessarily conclusive, but new information, an additional search area may be opened in the Indian Ocean.
Separately, a US navy official, referring to a guided-missile destroyer initially deployed to the Gulf of Thailand said: "The USS Kidd is transiting the Strait of Malacca, on route to the Indian Ocean."
A US surveillance plane was also believed to be heading to the area to join another US aircraft.
A second US destroyer, the USS Pinckney, is still in the Gulf of Thailand, but it was unclear if it would remain in the international search effort after this week, officials said.
|Uncertainty clouds search for Malaysian airliner
These moves followed reports that the Boeing 777 airliner's communication system continued to contact a satellite for a number of hours after the plane disappeared off radar as well as statements by Malaysian officials that the airliner may have doubled back after taking off from Kuala Lumpur.
So far, communications satellites have only picked up faint electronic pulses from the flight since it went missing, but the signals have given no indication about where the jet was headed nor its technical condition, a source close to the investigation told the Reuters news agency.
Planes were sent on Thursday to search an area off the southern tip of Vietnam where Chinese satellite images published on a Chinese government website reportedly showed three suspected floating objects. But they only saw ocean.
Dozens of ships and aircraft from 12 nations have been searching the Gulf of Thailand and the strait, but no trace has been found.
"It's such a vast area and with these little clues they really don't know where to start," said Al Jazeera's Scott Heidler reporting from Kuala Lumpur.
The search area has grown to 92,600sq km.