The prime minister of Malaysia announced in Kuala Lumpur that there was no longer any doubt that the missing Malaysian Airlines jetliner, Flight 370, crashed in the Indian Ocean.

Prime Minister Najib Razak said the conclusion was based on new analysis of data from an automated satellite system on the plane, performed by Inmarsat and the British national aviation safety agency. The analysis narrowed down the possible paths the Boeing 777 aircraft could have taken as it kept flying for hours after contact with ground controllers was lost on March 8, and it ruled out that the plane could have gone anywhere but the remote waters southwest of Australia, where there is no place the plane could have landed safely.

"It is therefore with deep sadness and regret that I must inform you that, according to this new data, flight MH370 ended in the southern Indian Ocean,” Mr. Razak said.

Just before the prime minister spoke, Malaysia Airlines officials informed relatives of the missing passengers and crew gathered at a hotel near Kuala Lumpur, and sent text messages to those elsewhere.

The hunt for the missing plane has focused on the southern Indian Ocean area in recent days, and an Australian naval vessel searched there on Monday after a military surveillance aircraft spotted what was described as possible debris from the missing jetliner.