KUALA LUMPUR, Malaysia — Murky satellite images that a Chinese science and defense agency said may show debris from the missing Malaysian Airlines jetliner provided a fresh clue Thursday in the search for the plane, pointing searchers to a location nearer to the plane’s original flight path south of Vietnam.
The discovery could provide searchers with a focus that has eluded them since the plane disappeared with 239 people aboard just hours after leaving Kuala Lumpur for Beijing early Saturday. Since then, the search has covered 35,800 square miles, first east and then west of Malaysia and even expanded toward India on Wednesday.
The Chinese sighting, if confirmed, would be closer to where the frantic hunt started.
The Xinhua report said the images from around 11 a.m. on Sunday appear to show ‘‘three suspected floating objects’’ of varying sizes in a 20-kilometer radius, the largest about 79 by 72 feet.
The images originally were posted on the website of China’s State Administration of Science, Technology, and Industry for National Defense. That site reports coordinates of a location in the sea off the southern tip of Vietnam and east of Malaysia.
But since the satellite images were taken four days ago, it is far from certain that whatever they show would be in the same location now.
No other governments have confirmed the Xinhua report, which did not say when Chinese officials became aware of the images and associated them with the missing plane.
Two-thirds of the passengers were Chinese, and the Chinese government has put increasing pressure on Malaysian officials to solve the mystery of the plane’s disappearance.
Malaysia’s civil aviation chief, Datuk Azharuddin Abdul Rahman, said Malaysia had not been officially informed by China about the images, which he said he was learning about from the news.
He said if Beijing informs them of the coordinates, Malaysia will dispatch vessels and planes immediately.
‘‘If we get confirmation, we will send something,’’ he said early on Thursday.
Until then, he urged caution. ‘‘There have been lots of reports of suspected debris.’’
On Wednesday, it was revealed that the last message from the cockpit of the missing flight was routine. ‘‘All right, good night,’’ was the signoff transmitted to air traffic controllers five days ago.
Then the Boeing 777 vanished as it cruised over the South China Sea toward Vietnam, and nothing has been seen or heard of the jetliner since.
Those final words were picked up by controllers and relayed in Beijing to anguished relatives of some of the people aboard Flight MH370.
The Chinese reports of the satellite images came after several days of confusing and conflicting statements from Malaysian officials.
Earlier Wednesday, the Malaysian military officially disclosed why it was searching on both sides of country: A review of military radar records showed what might have been the plane turning back and crossing westward into the Strait of Malacca.
That would conflict with the latest images on the Chinese website.