馬航班機在失聯後數小時內向衛星發送電子脈衝信號

The search for a missing Malaysian jetliner expanded toward the Indian Ocean on Friday, as new evidence emerged that the jet may have traveled for hours after it vanished.

Speaking anonymously, U.S. officials briefed on the investigation said the Boeing 777 sent automated electronic messages to satellites several hours after it disappeared from civilian radar Saturday.

The officials said the communications satellites detected faint messages, known as pings, which attempted to relay regular maintenance and other data about the plane's condition.

It is not clear whether the messages can provide information on the plane's location. It is also not clear whether the plane was in the air at the time the messages were sent.

Ships and planes from over a dozen countries have been searching for six days for the Malaysia Airlines plane and its 239 people on board, who were headed from Kuala Lumpur to Beijing.

The initial search focused on the Gulf of Thailand, where the airliner was last spotted by civilian radar. The Malaysian military has since said it may have tracked the plane hundreds of kilometers away, across the Malaysian peninsula in the Strait of Malacca.

On Thursday, White House spokesman Jay Carney said "an additional search area may be opened" in the vast Indian Ocean. It is the world's third largest ocean and is significantly deeper than the other search areas.預計搜尋馬來西亞航空公司失聯班機的範圍星期五將擴大至印度洋，新證據顯示這架班機在失聯後可能繼續飛行了幾小時。

未透露姓名的美國官員在介紹調查情況時說，這架波音777客機上星期六從民用雷達屏幕上消失後的幾小時內，自動向衛星發送電子信號。

有關官員說，通信衛星接收到微弱的電子脈衝信號，這種信號的設計用途是通報飛機的一般維護狀態以及其他數據。

目前還不清楚這些電子脈衝信號能否提供有關失聯班機所在位置的信息，而且也不清楚班機在發送信號時是否處於飛行狀態。

來自12個國家的船隻和飛機的搜尋已經持續了六天。這架班機載有239人，原定從吉隆坡飛往北京。

最初的搜尋集中在泰國灣，這架班機在那裏從民用雷達屏幕上消失。馬來西亞軍方說，可能探測到這架班機偏離航線數百公里，跨越馬來西亞半島到馬六甲海峽。

白宮發言人卡尼星期四說，可能要在印度洋廣大海域展開新的搜尋行動。印度洋是世界第三大洋，水深遠遠超過已經搜尋過的海域。