BEIJING, March 14 -- India has intensified its search operation for the missing Malaysia Airlines MH370 passenger jet by scouring the uninhabited islands in Andaman and Nicobar, Indian officials said on Friday.

Harmit Singh, spokesman for India's air force, navy and army command, said India began a land search using Dornier planes, but nothing had been spotted as of Friday afternoon.

The search for the missing Malaysian plane has expanded westward to the Indian Ocean and farther eastwards into the South China Sea after the multinational hunt entered the seventh day, but no hard evidence has been found yet.

The Boeing 777-200 aircraft, carrying 227 passengers and 12 crew members, vanished off the civilian radar screen about one hour after it took off in Kuala Lumpur International Airport at 0:41 a.m. (1641GMT) Saturday.

"Together with our international partners, we are pushing further east into the South China Sea and further into the Indian Ocean," Malaysia's acting Transport Minister Hishammuddin Hussein on Friday told a press conference.

Referring to comments from unnamed U.S. officials that engine data show that the plane has kept flying for hours after last contact, the acting minister said the international team are currently working on verifying detailed information, but "we have nothing to confirm at this moment."

A Reuters report earlier Friday said military data suggests the missing jetliner was diverted from its intended route from Kuala Lumpur to Beijing and was flown deliberately toward westward off course.

"As is the standard procedure, the investigation team will not publicly release information until it has been properly verified and corroborated with the relevant authorities," he said.

"We want nothing more than to find the plane as quickly as possible, but the circumstances have forced us to broaden our search," he added.

The Malaysian authorities on Thursday refuted news reports that a Malaysian passenger jet may have continued flying for some time after last contact, saying these reports are "inaccurate."

"We checked with Boeing and Rolls Royce, who said the reports are not true," Hussein reaffirmed at the press conference.

As to the two oil slicks sighted by the authorities in the South China Sea, about 110 km south of last point of contact with Flight MH370, the official said the test result of the samples collected from the slicks showed they are not linked to the missing passenger jet.

More than 80 ships and planes from 13 countries are now combing the waters on both sides of the Malaysian peninsula to locate the missing plane.

Chinese forces, including eight vessels and five helicopters, have covered 45,763 sq. km as of 12 a.m. Thursday, after continuous searching for 100 hours in the South China Sea, according to the China Maritime Search and Rescue Center.

Besides, Chinese merchant ships are traveling in the Strait of Malacca and will help provide assistance.

At the request of Malaysia, Pentagon officials said that the U.S. Navy 7th Fleet is moving westward one of its ships, the USS Kidd, into the Strait of Malacca.

Vietnamese officials at the Search Command Center in Phu Quoc island said that five aircraft and eight boats have been sent to search the new areas and there are also four helicopters on standby to provide reinforcements if necessary.

Meanwhile, Singapore and Malaysia are sending flights to the reported location in South Vietnam where possible debris of the missing flight was spotted by Chinese satellites Thursday and the search proved to be futile.