BEIJING -- A Singaporean vessel participating in the search for the missing Malaysia Airlines plane has informed Vietnamese authorities that it has found some "suspicious objects" that may be from the missing aircraft, Vietnamese media said Sunday afternoon.
It was not immediately clear where the objects were discovered or what they were. Aircraft and ships were searching an area of about 3,900 square miles off the southern tip of Vietnam in the waters of the Gulf of Thailand and the South China Sea.
Vietnamese boats on Sunday reached an oil slick spotted late Saturday by Vietnamese surveillance aircraft, but found no sign of the Malaysia Airlines Flight MH370, Agence France-Presse reported. The jet went missing early Saturday with 239 people aboard en route from Kuala Lumpur to Beijing.
Meanwhile, the Malaysian Maritime Enforcement Agency said one of its patrol ships had found a large oil slick 100 nautical miles from the city of Tok Bali on Sunday, the agency's director-general said at a news conference.
The director-general, Mohd Amdan Kurish, said the ship was ordered to collect samples of the oil to determine if it came from the plane, Malaysia's state-run Bernama news agency reported.
If the plane did crash into the sea, "obviously we will find clothes, bags and debris that float," he added, according to Bernama. Fishermen working in the area were also going to be interviewed by the agency as part of the search operation.
With no wreckage yet to examine, investigators were also probing the identities of at least two passengers who apparently used stolen passports -- one from Italy, another from Austria -- to board the plane.
Malaysia's acting transportation minister, Hishammuddin Hussein, said at one point Sunday that authorities were looking at four passengers "said to have been traveling on fake passports." He gave no further details, and officials later spoke of only two suspected cases, creating some confusion.
Azharuddin Abdul Rahman, Malaysia's director-general of civil aviation, said at a news conference in Malaysia that investigators had closed-circuit TV footage of the two men traveling on the European passports.
China's ambassador to Malaysia, Huang Huikang, said the embassy was investigating whether the two had proper documents to go to Beijing, state-run CCTV reported.
Hugh Dunleavy, head of Malaysia Airlines' commercial operations, told reporters in Beijing: "As far as we are aware, every one of these people onboard that aircraft had a visa to go to China. Which means those passports were in possession of the Chinese Embassy before those visas were issued."
However, Beijing has a policy whereby some passengers in transit to third countries can stay in the Chinese capital for 72 hours without a visa, so the two men may have not needed to apply for a Chinese visa if they had tickets to another destination.
London's Telegraph newspaper said it had confirmed with two ticketing agents for China Southern Airlines -- which had a code-share arrangement with Malaysia Airlines for the flight -- that the two men were booked to fly onward to Amsterdam on the airline KLM Saturday morning. The paper said the two tickets were numbered consecutively, suggesting they were bought at the same time.
As the search for the aircraft continued, the head of Malaysia’s air force told reporters at a news conference that military radar indicated that the missing
But Rodzali Daud gave no further details, adding only that investigators "were trying to make sense" of the information.
The airline's CEO said that if planes veer from their flight plan, they are supposed to inform air traffic control, but no distress call or signal was received from the missing aircraft.
Several Chinese search ships arrived in the vicinity of the suspected crash site on Sunday. Australia offered to send aircraft to join the search as well.
More than half of the passengers aboard the missing flight were mainland Chinese, and Malaysia Airlines said it would fly some family members from Beijing to Kuala Lumpur as early as Monday to await word on their relatives' fate. The airline was working with Chinese and Malaysian officials to get some of the next-of-kin passports and visas.