PHU QUOC ISLAND, March 11 — Vietnamese authorities today said they are bracing for the worst in the search for Malaysia Airlines (MAS) flight MH370 that is now missing for over three days.

Vietnam’s deputy transport minister Pham Quy Tieu said, however, that the search for the missing jet will continue and that 10 aircraft were sent out today.

“We don’t have much hope of good things coming out from the flight,” Pham told reporters at Phu Quoc airport here today.

“We don’t expect the worst situation, but we will prepare for it. We will co-operate with the Kien Giang province to prepare for rescue activities,” he added.

Pham also said Vietnam hopes to locate the missing plane carrying 239 passengers in order to provide their family members the necessary answers in the continuing mystery.

“Vietnam will do our best,” he said.

The waters south of Tho Chu island near the southern edge of Vietnam is the site that has yielded the most sightings of “debris” from the plane, although all later proved to be false alarms.

The sightings began from the very first day MH370 was confirmed as missing on March 8, and has continued since.

On Sunday, an oil slick was spotted that search teams believed were from the Boeing 777, but later tests revealed this to be from bunkering oil.

Search and rescue efforts at Checkpoint Igari south of Tho Chu — the location of the MAS plane prior to it losing contact with ground controllers — was yesterday enlarged to cover a radius of 100 nautical miles, up from the original 50.

Another search zone was also formed in the Straits of Malacca, on the opposite side of peninsular Malaysia, after military radar suggested the flight may have attempted to turn around.

No trace of the plane and its passengers has surfaced, frustrating rescuers and baffling investigators alike.

There were 239 people on board flight MH370, including 12 crew members and two infants.